Implantable vascular access port with dual, high-flow trans-chamber and low-flow, access, and needle lock for high-flow

ABSTRACT

An implantable vascular access port has a main port body with one or more hollow internal chambers formed therein each with a floor at the base of the internal chamber. The port body has an outlet aperture formed in a sidewall there of the internal chamber. One or more parallel, lateral, or angled-access apertures, relative to the port floor and associated septa are located opposite the outlet aperture in the main port body in a sidewall there of (parallel or lateral or angled-access aperture or septum), with at least a one perpendicular-access aperture and septum located opposite the floor of the internal chamber(s). The port chamber in the area of the outlet aperture has an at least partially conical shape directionally aligned with the parallel or lateral or angled-access aperture and septum, with said outlet aperture in contiguity a reversible outlet tube or port body needle locking mechanism.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of application Ser. No.16/825,884 filed Mar. 20, 2020, now U.S. Pat. No. 10,960,196.

BACKGROUND OF THE INVENTION

This invention relates to medical devices implantable subcutaneously ina patient to facilitate access by medical personnel to the vascularsystem of the patient.

Subcutaneous vascular access ports are implantable medical devices,which allow for the repeated access to a patients central venous systemover time in order to inject various medicines and draw blood forvarious laboratory tests. Vascular ports are particularly useful incancer patients in order to administer chemotherapy over prolongedperiods of time often under the conditions of poor venous access.Vascular access ports can also be used to inject iodinated contrastmaterial for diagnostic computerized axial tomography (CAT) scans whichare often performed in cancer patients. Subcutaneous vascular accessports are designed to facilitate the reliable and rapid access to thecentral venous system over time by medical professionals. Thesubcutaneous location is advantageous since the overlying soft tissuesact as a barrier to infection when not in use, i.e. when not accessedwith a specialized needle. Single lumen and double lumen ports existrespectively for the administration of a single medication and twomedications simultaneously.

A typical subcutaneous access port is constructed of a main port bodyconsisting of a hollow largely cylindrical access chamber with a solidimpenetrable floor, which is farthest away from the skin, and a moresuperficial penetrable flexible septum or diaphragm that is close to theskin surface, allowing for repeated needle access to the hollow chamberat different points in time. The impenetrable port body including thesides and floor are often constructed of a metal alloy or plasticmaterial with varying degrees of radiopacity. The penetrable septum isusually formed from a resilient deformable material such as a siliconeelastomer and is radiolucent. This enables fluoroscopically guidedaccess when the port cannot be readily accessed with palpation alone.The standard port access needle is a hollow beveled needle called aHuber needle, which is manufactured in various lengths and gauges,designed not to core or remove portions of the silicone septum. Thebevel or cutting edge of a Huber needle is almost perpendicular to theneedle shaft resulting in parting of the silicone without making a hole.Huber needles typically range in length from 0.5 inches to 1.5 inches inlength and 22 to 19 gauge in diameter. The standard cylindrical accesschamber typically has a rigid tubular outlet aperture or conduit on onesidewall, which can then be connected to a more flexible catheter, whichis then usually inserted into the central veins of a patient, such asthe internal jugular vein or the subclavian vein. The flexible cathetermaterial can be cut to the appropriate length for an individual patientand is typically made of either silicone rubber or polyurethane. Thecatheter can then be inserted into the desired vein by a removablelarger plastic sheath system; typically a peel-away sheath made byvarious manufactures, which contains perforations, which can be split,removing the sheath in two halves, after successful catheterintroduction. The port and the attached catheter, in continuity with thecentral venous system, thereby allows for reliable central venous accessover time. Palpating the port body and inserting a needle through theskin and subsequently through the septum into the chamber, until theneedle tip hits the back wall establishes venous access, an attempt canthen be made to aspirate blood. The ability to freely aspirate bloodfrom the port coupled with the ability to readily inject a saline orother similar solution into the port with minimal resistance isconsidered satisfactory clinical proof of the establishment ofsatisfactory vascular access.

A generic example of an access port is shown in sagittal cross sectionin FIG. 1 and coronal cross section in FIG. 2 . This generic known portdevice 20 includes a main port body 22, which approximates afrusto-conical shape, having a hollow chamber 24, which is essentiallycylindrical in shape. The chamber 24 has a flat impenetrable floor orbottom surface 26 and a flexible penetrable and deformable septum 28,exemplarily of silicone elastomer, which is designed to receive anon-coring hollow access needle or Huber needle to establish vascularaccess. The septum 28 includes a thick central portion 21 and a thinneredge portion or flange 23 for placement in a circumferential channel orgroove 25, in order to anchor the septum in place in the main port body22. The access port 20 shown in FIGS. 1 and 2 is has an outlet aperture30 on the inside of the port chamber which leads to an attached hollowoutlet tube 32, subsequently attaching to a proximal end 34 of anattached intravascular catheter 36, thus allowing for continuity of flowbetween the port chamber 24, outlet aperture 30, outlet tube 32, andultimately the proximal end 34 of the attached intravascular catheter36. The outlet aperture 30 is formed in a sidewall of the main portchamber 24 within the port body 22, at some distance above the floor 26.The generic port is implanted in the subcutaneous tissues of the upperchest wall and then the proximal end 34 of the catheter 36 is thenattached to the outlet tube 32 prior to inserting the distal end of thecatheter 36 into one of the central veins such as the internal jugularvein or subclavian vein as shown in FIG. 22 .

Although vascular ports, as shown implanted in FIG. 22 , are effectivedevices they can malfunction over time sometimes requiring surgicalrevision or replacement. Problems that can occur include catheterthrombosis, fibrin sheath formation surrounding the intravascularportion of the catheter, and delayed catheter tip migration into anundesirable location. A fibrin sheath is a biological film or coating,which can form around the intravascular portion of the catheterincluding the tip, restricting or completely blocking flow (FIG. 23 ).Clot dissolving drugs such as tissue plasminogen activator (TPA) areinitially tried to dissolve intracatheter clot and or a surroundingfibrin sheath. If clot-dissolving drugs are ineffective forreestablishing patency when intracatheter clot is present, surgicalrevision is required. If clot-dissolving drugs such as TPA cannotdissolve or eliminate a surrounding fibrin sheath, mechanical removal ofthe sheath can be attempted via an endovascular striping procedure witha loop snare (FIG. 24 ) or alternatively surgical revision of the portcan be performed. Endovascular stripping typically entails puncturingthe femoral vein in the groin area with placement of an intravascularsheath, diagnostic catheter, subsequently placing a loop snare throughthe diagnostic catheter and then around the tip of the fibrin sheathcovered port catheter under fluoroscopy (FIG. 24 ). After snaring theport catheter, traction is applied to strip off the overlying attachedfibrin sheath or biofilm. This procedure is often effective in removingthe fibrin sheath but can result in fracturing the catheter with aresultant intravascular foreign body, which can then migrate to theright heart and or pulmonary circulation (FIG. 25 ). Similarly, if thecatheter tip migrates or flips into a undesirable location such as theinternal jugular vein, the tip can be snared from below, after gainingvenous access via the femoral vein, and be repositioned or pulled downinto the superior vena cava or right atrium (FIG. 26 ). It may beclinically desirable to have simpler, safer, simpler, and moreefficacious methods for maintaining secondary patency and functionalityof vascular access ports.

If the catheter (tunneled or non-tunneled) exits the skin, unlike aport, which is wholly contained under the skin, additional establishedmethods are available to remedy the aforementioned problems. Theselargely center on the ability to place a wire through the proximal hubof the catheter. Wire advancement and manipulation through the catheterlumen can be used to dislodge intraluminal clot or disrupt an overlyingfibrin sheath, often reestablishing patency of the catheter. Small wirebrushes typically used for obtaining cytology samples from the mucosalsurfaces of the bile ducts or ureters have also been used for thepurpose of reestablishing catheter patency in lieu of a simple wiremanipulation. If the wire or brush manipulations are unsuccessful, thecatheters can be exchanged over a wire for a new catheter. In addition,balloon disruption of the intravascular fibrin sheath, after removal ofthe dysfunctional catheter over a wire (typically accomplished through avalved vascular sheath) can also be performed prior to placement of thenew catheter, to ensure there is no remaining fibrin sheath adherent tothe vessel wall.

During port placement, difficulty can occur with the formation of aredundant loop of catheter in the soft tissues, which can be difficultto straighten out or reduce. This typically occurs in the subcutaneoustissues near the venous entrance site after initial intravascularcatheter placement, via a lubricious plastic tube or peel-away sheath,which is advanced into the vein and then removed. The redundant catheterloop results in kinking of the catheter and resultant devicemalfunction. The redundant loop can at times be difficult to remedy,requiring extensive soft tissue manipulation or surgical revision. Itmay be clinically desirable to have more reliable and efficaciousmethods for initial catheter placement and ways of fixing such catheterplacement complications.

Port removal can on occasion result in inadvertent cutting or separationof the catheter from the port body with a resultant intravascularforeign body, and the catheter is often difficult to identify andpalpate during surgical removal, making removal of the port and theattached catheter difficult, particularly if there is abundantsurrounding scar tissue or the catheter is old, degraded, and fragile.During this process the catheter can be inadvertently cut or becomedisconnected with consequent creation of a loose intravascular foreignbody. Surgical port revision or replacement can also be a lengthyprocess, first the old port and catheter must be removed and then a newport must be placed in a stepwise fashion similar to initial placement.A port design to better address the aforementioned issues may bedesirable.

Standard port design does not allow for high flow applications likeapheresis or dialysis, most available devices are not able to achievethe necessary flow rates. It may be desirable to have a vascular accessport which maintains easy or routine needle access for low flowapplications like medication administration and blood draws while at thesame time allowing for high flow applications such as apheresis ordialysis. The C.R. BARD PowerFlow port (US Patent ApplicationPublication No. 2014/0207086) allows for high flow applications such asapheresis but is difficult to access requiring specialized nursingtraining, limiting its clinical utility for routine low flow intravenousaccess in particular. The design necessitates a number of unique stepsto access the port, dissimilar from the methodology to accesstraditional ports, preventing routine use by lesser-trained nursingpersonal. Additionally, a plastic deformable angiocatheter is advancedat an angle through a rigid access channel in the device, which canpotentially kink or crimp, reducing flow rates and preventing reliablevascular access. These design features significantly limit itseffectiveness at addressing the aforementioned clinical problems.

US Patent Application Publication No. 2005/0085778 describes a portapparatus 38 (FIGS. 3 and 4 herein) that provides a suboptimal solutionto some of the aforementioned problems by theoretically enablingplacement of a guide wire 40 through a directionally aimed curved portchamber 42, similar in shape to a bubble pipe bowl or old-fashioned eartrumpet, utilizing a specialized curved needle (WYR-GYD needle) 44 witha pencil point tip and a side hole 46 located near its distal end,approximating a right angle. After penetrating the port septum 48 at aspecific orientation, the curved WYR-GYD needle 44 in combination withthe saucerized port chamber 42 direct the wire 40 toward the exitingcatheter 50 (FIG. 4 ). The design requires utilization of a specializedcurved WYR-GYD non-standard needle 44 to access the port 38 at aspecific orientation, increasing access difficultly over currentdevices, particularly without the aide of fluoroscopy or specialtraining. These requirements may significantly limit the devices utilityfor routine clinical work by healthcare professionals over currentdevices. The stocking of specialized curved WYR-GYD needles 44 forroutine clinical access for a single specific device is alsoimpractical. The saucerized or sloping port chamber 42 may also make itdifficult to access the port 38 with a standard straight or 90 degreeHuber needle since the depth varies from one side of the port to theother, making it difficult to advance the needle to the needed depth forreliable vascular access in a consistent manner. There is no other meansof accessing the port for routine clinical work. Even if the port issuccessfully accessed with the special non-standard curved WYR-GYDneedle 44, the wire 40 is advanced at a 90-degree angle, a distinctmechanical disadvantage with associated increased resistance, therebylimiting wire advancement, manipulation, and steerability. In additionto limiting wire manipulation the 90-degree orientation of the wire,limits the ability to perform other interventions such as exchange ofthe device over a wire in order to facilitate surgical revision.Additionally, the design does not allow for high flow applications suchas apheresis or dialysis. These design features significantly limit itseffectiveness at addressing the aforementioned clinical problems.

OBJECTS OF THE INVENTION

It is an object of the present invention to provide an improved vascularaccess device and/or an associated surgical method, which addresses theafore-mentioned problems.

It is a more specific object of the present invention to provide animproved vascular access port and/or an associated surgical method thatenables both routine low-flow vascular access and special high-flowvascular access.

These and other objects of the present invention will be apparent fromthe drawings and descriptions hereof. Although every object of theinvention is considered to be attained by at least one embodiment of theinvention, there is not necessarily any single embodiment that achievesall of the objects of the invention.

SUMMARY OF THE INVENTION

The present invention provides an improved single lumen vascular accessport and/or an associated surgical method, where the port contains atleast two different needle access points or apertures, at least one ofwhich is a standard superficial penetrable flexible septum or diaphragmthat is located close to the skin surface for routine clinical access(perpendicular- or vertical-or top-access aperture) to be entered at ornear 90 degrees relative to an internal-chamber floor surface, and atleast a second separate parallel-access or lateral access aperture witha penetrable septum (to be entered parallel to or at an acute anglepreferably less than about 40° relative to the port chamber floor) tofacilitate the ergonomic advancement through the port chamber (then intothe outlet tube and an attached intravascular catheter) of variousintravascular wires, brushes, devices or tools for maintaining secondaryport patency by removing or dislodging intraluminal clot and or anadherent fibrin sheath attached to the intravascular catheter. Thelateral access aperture may have a steeper angle relative to the portfloor, up to about 70°, in order to improve aperture palpation andidentification along with the ergonomic needle advancement into thelateral access aperture, particularly important for the reliableexecution of the high flow applications of apheresis and dialysis ascontemplated herein. The outlet tube is similarly angled to maintain acollinear relationship with the lateral access aperture such that anaccess needle advanced through said lateral access aperture can readilytraverse the port chamber to enter the outlet aperture and outlet tubein a straight-line pathway (lateral or straight-line access aperture).In addition, the angled more inferiorly positioned outlet stem lowersthe overall center of gravity of the port body and limits tipping ortilting of the implanted device which is accentuated by drag created bythe attached catheter to said outlet stem.

The present invention provides an improved single lumen vascular accessport and/or an associated surgical method, where the port contains twodifferent needle access points or apertures, one of which is a standardsuperficial perpendicular- or top-access aperture with a penetrableflexible septum that is located close to the skin surface for routineclinical access for low-flow applications (needle placed at leastsubstantially perpendicular to the upper and lower walls of the portdevice as well as the adjacent overlying skin), and a second, separatelateral access aperture or straight-line-access aperture for high-flowapplications and other interventions (needle placement or insertionstraight across the internal chamber of the port device to an outletaperture in the internal chamber, parallel to or at an acuteangle—preferably a small or shallow angle—relative to the port chamberfloor and lower port wall) with a penetrable septum to enablefluoroscopic repositioning of a previously placed undesirably migratedintravascular port catheter tip position by advancement of a needle andsubsequently a steerable wire through the lateral sidewall orstraight-line-access aperture and subsequently the catheter underfluoroscopy.

The present invention provides an improved single lumen vascular accessport and/or an associated surgical method, where the port contains twodifferent needle access points or apertures, one of which is a standardsuperficial penetrable flexible septum or diaphragm that is locatedclose to the skin surface for routine clinical access (perpendicular- ortop-access aperture for low-flow applications), and a second separatelateral access aperture- or straight-line-access aperture with apenetrable septum to enhance the safety of port removal over a wirepreventing inadvertent cutting or dislodgement of the port catheter withresultant intravascular foreign body creation.

The present invention contemplates an improved single lumen vascularaccess port and/or an associated surgical method, where the portcontains two different needle access points or apertures, one of whichis a standard superficial penetrable flexible septum or diaphragm thatis located close to the skin surface for routine clinical access(perpendicular- or top-access aperture for low-flow-rate applications),and a second separate lateral access aperture or straight-line-accessaperture with a penetrable septum to enable an initial wire directedport catheter placement, helping to both steer the catheter to a givenvascular location and improving catheter pushability during deployment,or to help remedy immediate or delayed port catheter placementcomplications such as a redundant and/or kinked often extravascularsubcutaneous catheter loop.

The present invention provides an improved single lumen vascular accessport body design and/or an associated surgical method, where the portbody contains two different needle access points or apertures, one ofwhich is a standard superficial penetrable flexible septum or diaphragmthat is located close to the skin surface for routine clinical accessfor low-flow applications (top- or perpendicular-access aperture), and asecond separate lateral access aperture or straight-line-access aperturewith a penetrable septum to enable over-the-wire port exchange for amalfunctioning port or to exchange it for different tunnel intravascularaccess apparatus such as a Hickman catheter or plasmapheresis catheter.

The present invention provides an improved vascular access port and/oran associated surgical method to accommodate various wires orendovascular devices so they can be used to their best mechanicaladvantage or working angle to help maintain secondary port patency orfacilitate port exchange (at or near 180 degrees) via thestraight-line-access aperture.

Pursuant to a feature of the present invention, in traversing thestraight-line access a needle crosses the internal chamber of the portdevice along a linear path or direction to traverse an output apertureon an opposite of the chamber. The straight line may be angled at anacute angle relative to the vertical or normal (and necessarily at anacute angle to the skin surface and the horizontal or upper and lowerwalls or floor of the port device) so that the linear path of needleinsertion inclines downwardly from the lateral access aperture to theoutlet aperture and contiguous outlet tube. The collinear orientation ofthe lateral access aperture and outlet tube facilitates trans-chamberneedle entrance into the outlet aperture and outlet tube oralternatively into a port body channel contiguous with the outletaperture and the outlet tube. The lateral access aperture may have anangle relative to the port floor or lower wall of up to approximately 70degrees in order to improve the ergonomics of reliable lateral accessaperture identification and access needle placement. The outlet apertureand contiguous outlet tube being positioned at a lower end of the portbody militates against tipping or pivoting of the port device inresponse to catheter drag on the outlet tube. The outlet tube beingparallel to the angled straight-line access needle path may be similarlyangled relative to the vertical and acutely angled relative to the floorof the port chamber, be it a single or a double lumen version of thedevices described herein.

Preferably, the outlet aperture communicates with an outlet tube or stemthat, at least on an upstream side contiguous with the outlet apertureand the internal chamber, is co-linear with the linear path or directionof access of the needle from the lateral sidewall orstraight-line-access aperture to the chamber outlet aperture. At theupstream side, the outlet tube (or in a contiguous adjacent channel inthe port body communicating with the internal chamber) is providedinternally (within its lumen) with a male element (such as a rib, a nub,a lug, a tooth, etc.) or a female element (typically a groove or arecess) that mates with a corresponding female or male element on theaccess needle to temporarily lock or fix the needle to the port body.The coupling or locking element(s) may be located in the outlet tubeitself or upstream within a port chamber channel, opposite the lateralaccess aperture, in contiguity with the outlet tube or stem. Thestraight-line access needle, once locked in place, eliminates turbulenceand therefore limitations to high flow applications inherent toutilizing the top or perpendicular access aperture for this purpose. Astraight tube or conduit has lower frictional losses or turbulencerelative to a capacious chamber or angled conduit. The use of a rigidneedle for this purpose reduces the risk of kinking inherent inutilizing deformable thin walled plastics (angiocatheter) for access,particularly if advanced at an angle. The interlocking needle or snaplock mechanism facilitates needle stability and creates a tight sealenabling high-flow procedures (such as apheresis or dialysis),preventing backflow. At least one of the two male and female componentsof the snap lock mechanism may be composed of an elastomeric materialsuch as plastic. A number of options are available when attempting toutilize a port for high flow access procedures such as apheresis ordialysis: two separate single lumen ports placed with one serving as thevenous access and the other for the venous return; single lumen portplacement, serving as the venous access and using peripheral intravenouscannulation for the venous return; or placement of a dual lumen portwith both venous access and return capabilities. The interlocking needlemechanism also provides stability for other contemplated methods andprocedures described herein such as wire advancement through theattached intravascular catheter facilitating port placement, portcatheter repositioning, maintenance of secondary patency, port removal,and over the wire port exchange.

The present invention provides an improved vascular access port bodyshape, port chamber shape, and outlet aperture configuration to bestguide the placement of various wires, devices, or tools, via theaforementioned lateral sidewall or straight-line-access aperture orapertures through the port chamber, into the port chamber outletaperture, and subsequently the attached exiting intravascular catheter.

The present invention provides an improved vascular access port and/oran associated surgical method to facilitate fibrin sheath striping (withan intravascular loop snare) over a needle and subsequently a wireplaced through the straight-line-access port aperture to decrease thelikelihood of intravascular catheter fragmentation and intravascularforeign body creation, thereby restoring or maintaining port catheterpatency in a more effective and safe manner.

The present invention provides an improved vascular access port and/oran associated surgical method wherein a second port aperture orpenetrable septum allows for an alternative skin puncture site, for theadministration of medications, if one of the apertures is less desirablefor routine clinical use (hematoma or local skin site wound orirritation for example), or for the simultaneous administration of asecond miscible or compatible medication.

The present invention provides an improved double lumen vascular accessport and/or an associated surgical method, where the port contains atotal of four different needle access points or apertures, specificallytwo juxtaposed perpendicular-access adjoining apertures for routineclinical use and two adjoining straight-line-access apertures formaintaining secondary patency enabling all of the aforementionedproperties, functions, and methods of the single lumen device. The pathsof straight-line access may be angled in towards one another, to providespace at the outside for manipulating two needles simultaneously, ifnecessary. Also the paths of straight-line access may be angleddownwardly to place the access apertures closer to the skin surface tothereby facilitate aperture locating and needle deployment. Such adouble lumen vascular access port may be used in carrying out high flowapplications such as dialysis with both inlet and outlet needles inaddition to apheresis.

A single lumen access port pursuant to the present invention contains atleast two different needle access points or apertures, at least one ofwhich is a standard superficial penetrable flexible septum or diaphragmthat is located close to the skin surface for routine clinical access(perpendicular- or vertical- or top-access aperture), and a secondseparate straight-line-access aperture or lateral access aperture with apenetrable septum (to be entered parallel to or at an acute anglerelative to the port chamber floor) to facilitate the placement ofvarious intravascular wires, devices or tools in order to help maintainsecondary port patency, facilitate initial port placement, improve thesafety of port removal, enable over-the-wire port exchange, andhigh-flow access (apheresis and dialysis). Physicians will primarilyutilize the secondary, straight-line-access or working aperture for theaforementioned purposes under fluoroscopic guidance, while nurses mayprimarily use the perpendicular-access aperture for routine clinical use(generally, applications with low flow rates) without fluoroscopy, thelatter in an identical manner to ports currently in the market place.Specialized nurses, such as apheresis or dialysis nurse may also betrained to access the lateral or straight-line access aperture for highflow applications such as apheresis or dialysis. The lateral orstraight-line access aperture, which is located typically on thesidewall of the port body opposite the exiting outlet tube and catheter,allows for the advancement of various devices including but not limitedto a wire at the optimal working angle (at or near 180 degrees) to enterthe exiting intravascular catheter. While a lateral access port istypically disposed in a sidewall of a port body, the word “lateral”denotes the port as being “to the side” of a routine-maintenance accessport in a top or upper wall of a vascular access port body. The shallowangle lateral or straight-line access aperture provides the ideal angleof approach for advancing a needle and subsequently a wire or otherdevices in order to engage or enter the exiting outlet tube andsubsequently the intravascular catheter, located on the opposite end orside of the port body in order to perform various intravascularprocedures with the goal of restoring or improving vascular port patencyand function. The lateral or straight-line access aperture (which may bedisposed in a parallel or angled plane, relative to the lower wall orfloor of the port device) provides the ideal angle of approach for wireadvancement, manipulation and steerability both before and afterentering the exiting catheter and ultimately within the vascular system.The goal of the design is to not substantively alter the technique orequipment required for routine clinical port access by nurses or otherhealthcare personnel relative to current devices. Therefore there is noneed for new training or new equipment for routine access purposes.

The port body shape may be configured to optimally accommodate thelateral or straight-line access aperture(s) and guide the placement ofinitially a needle and subsequently various wires, devices, or tools,via the aforementioned straight-line-access aperture or aperturesthrough the port body into the exiting outlet tube and ultimately theintravascular catheter. For instance, the port body may be wideropposite the exiting catheter in order to accommodate the placement ofone or more straight-line-access apertures. One version of the port maytherefore assume a horseshoe shape with a more tapered or conical endlocated on the exiting catheter side and an opposite wider endincorporating the straight-line-access aperture or apertures. An overallrounded port chamber may passively help guide the needle toward saidconical end. Rounding of the edges of the port body along the widerhorseshoe-shaped end may reduce friction for easier port placement,removal, or exchange. Alternatively the port body may assume on an outerside more of a smooth elongated, oblong, or teardrop shape in order toreduce friction during port removal or exchange after scar tissue hasdeveloped, while placing traction on the port with a clamp. A moreconical or tapered inner contour of the port chamber opposite thestraight-line-access working aperture or apertures facilitates or helpsguide the entrance of the needle into the exiting outlet tube andultimately a wire into the intravascular catheter and subsequently intothe vascular system. Alternatively the port body and or chamber may beconfigured in a more conventional cylindrical shape, frusto-conicalshape, or preferably an ellipsoid or spheroid shape (true sphere oroblate sphere) since this latter design fosters circular motion andmixing of the injected fluids, minimizing dead space within the chamber.Acute edges and corners result in sudden directional changes in fluidflow through the port chamber, creating dead zones, cell shearing,platelet activation and clotting. Fluoroscopic guidance may assistplacement of an access needle into the rounded or semicircularstraight-line-access port aperture or diaphragm and subsequently directthe needle into the outlet tube while maintaining the most ergonomicshape for minimizing dead space and activation of the clotting cascadewithin the port chamber. Palpable features, either a concavity or anelevation incorporated into the straight-line-access or lateral accessaperture, facilitates needle access without fluoroscopic guidance. Forexample, a skin covered frusto-conical feature (palpable depression,concavity, or inwardly tapering recess) helps guide the needle toward asmaller deeper inner septum, at its junction with the port chamber wall,in alignment with the outlet aperture on the opposite port chamber wall.

Different outer port body shapes and inner chamber sizes and shapes mayconfer different advantages. For example, the outer port body can befrusto-conical, elliptic frusto-conical, ellipsoidal ovoid, torpedoshaped, or teardrop shaped but contain a smaller inner cylindrical,frusto-conical, elliptic frusto-conical, spheroid or ellipsoid portchamber (constituting similar or differing shapes of the respective portbody and chamber) which allows room for a frusto-conical, ellipticfrusto-conical, frusto-pyramidal or other shaped skin covered palpabledepression or inwardly tapering recess, leading to a smaller innerseptum, serving to guide or align the access needle with the outletaperture and outlet tube. The wider outer component is easier to palpateand enter while the smaller inner portion more effectively guides oraligns the access needle to the outlet aperture on the opposite side ofthe chamber. For example, an outer frusto-conical port body shape with aflat dome optimizes palpation for low flow vertical access while aspheroid (true sphere or oblate sphere) or ellipsoid inner chamberoptimizes flow dynamics within the chamber, limiting eddy currents andthereby minimizing intra-chamber thrombus formation. Differing geometricshapes and sizes of the respective port body and chamber may alsoenhance palpable lateral access aperture features such as allowing roomfor the incorporation of the inwardly tapering recess or palpabledepression, leading to a smaller inner septum, serving to guide or alignthe access needle with the outlet aperture and outlet tube.

The straight-line-access needle may be a non-coring straight Huberneedle. In that case, however, the almost perpendicular orientation ofthe cutting edge while allowing for the needle to separate or part thesilicone likely results in some deflection of a wire placed through theneedle. Using a Seldinger needle may obviate this potential mechanicaldisadvantage, this being a straight beveled needle containing a beveledsolid stylet that projects out from the end of the needle,simultaneously preventing coring of the silicone diaphragm.

In one embodiment of the invention, a port body or a portion thereof inaccordance with the invention is at least partially radiopaque while therespective perpendicular-access and straight-line-access apertures,along with the outlet aperture, are radiolucent thereby facilitatingfluoroscopically guided needle placement through either aperture but maybe particularly useful for the straight-line-access aperture orapertures, in preparation for various vascular interventions with theprimary goal of maintaining secondary port patency or for performinghigh flow procedures such as plasmapheresis or dialysis. For exampleonly the sidewalls of the port body may be radiopaque or partiallyradiopaque while both the perpendicular-access aperture and thestraight-line access aperture may be radiolucent along with the outletaperture. The straight-line-access and or perpendicular-access aperturesmay have enhanced radiopaque edges to facilitate fluoroscopic needleplacement. Alternatively, the port body may be largely radiolucent withcomplete or partial radiopaque edges or rims added to the otherwiseradiolucent straight-line-access aperture, perpendicular-accessaperture, and outlet aperture to facilitate fluoroscopic needleplacement as well. This is an important port body design feature sinceaccessing the straight-line-access aperture(s) may be more difficultthan the standard perpendicular-access aperture(s) by palpation aloneand once accessed any procedure to remedy malfunction of the vascularaccess port may invariably be guided by fluoroscopy, typically performedby a physician such as a radiologist.

The perpendicular-access aperture, whether in current clinical vascularaccess devices or the device described herein, is optimized for needleaccess by palpation alone and is typically performed by a nurse;however, fluoroscopy can be also utilized for difficult clinicalscenarios either for confirmation of correct needle position orfluoroscopically guided direct needle access. The straight-line-accessaperture only need be occasionally accessed for the primary purpose ofhigh flow applications such as apheresis or dialysis, addressingvascular port malfunction, catheter repositioning, port removal or portexchange. However, the straight-line-access aperture may also be usedfor routine clinical use, if the perpendicular-access aperture or septumis inaccessible due to overlying cutaneous or subcutaneous pathology, orif simultaneous administration of miscible or compatible medications isdesirable. The straight-line-access aperture may be accessed bypalpation of various features described herein or by fluoroscopy asneeded, if difficultly is encountered by a specialized apheresis nursefor example, or if a physician is performing one of a number orfluoroscopically guided interventions described herein.

These devices used to maintain port patency and optimal function includebut are not limited to steerable wires, microbrushes, and microballonsand are typically placed under fluoroscopic guidance by a physician suchas a radiologist. The devices used to remedy catheter malfunction havebeen previously described for accessible vascular access devices such astunneled Hickman catheters but the novel straight-line-access apertureand associated methods described herein enable their effective use inthe setting of an otherwise inaccessible subcutaneous vascular accessport. The unique aforementioned second, straight-line-access aperture orapertures and port body and port outlet design facilitates the placementand usage of such devices. These devices may be placed through a larger18 gauge non-coring Huber or stylet-containing Seldinger needle is thentypically used to access the second perpendicular-access port forroutine clinical purposes (22 to 19 gauge) such as the administration ofdrugs. Utilization of the straight-line-access aperture and larger gaugeand possibly longer non-coring Huber or stylet-containing Seldingerneedle may only be needed on occasion to address vascular portmalfunction or perform a high flow procedure such as apheresis ordialysis. Slidable wire advancement through the straight-line-accessaperture via an 18 gauge Huber or Seldinger needle may be used torecanalize an occluded port catheter lumen and or disrupt a fibrinsheath surrounding the end of the port catheter in lieu of or incombination with TPA. A steerable wire may also be utilized toreposition a malpositioned catheter tip, which can migrate into anundesirable position such as the internal jugular vein for example. Theideal position for the catheter tip is generally considered to be thesuperior vena cava or the right atrium. Wire advancement into theinferior vena cava after placement through the straight-line-accessaperture and catheter allows for safer fibrin sheath stripping relativeto current methods. Femoral vein puncture allows for placement of anangiographic catheter and subsequently a snare around the moresuperiorly located wire and contiguous port catheter from an inferiorapproach under fluoroscopy. The snare can then tightened around portcatheter and traction can then be applied such that the fibrin sheath orbiofilm can be removed. The wire allows for safer and easier capture ofthe port catheter by securing the longer wire in the inferior vena cavaaway from the right atrium. More importantly the support of the wirelessens the likelihood and consequences of inadvertent fracturing of theport catheter. If the catheter were to inadvertently fracture from thefibrin sheath striping procedure, the loose piece may still be locatedon the wire and may be removed from the femoral access via the snare.Fibrin sheath striping without the use of a concomitant wire can resultin a loose intravascular foreign body, which can then migrate to theheart or pulmonary circulation. A silicon or latex microballoon may alsobe advanced through the 18 gauge Huber or Seldinger needle withsubsequent inflation just distal to the port catheter tip in order todisrupt a surrounding fibrin sheath or biofilm.

The ability to advance a needle and subsequently a wire through thestraight-line-access aperture(s) and the port's internal chamber canallow for more reliable initial wire-directed catheter placement or tohelp remedy immediate or delayed subcutaneous port-catheter placementcomplications such as a redundant and or kinked catheter loop in theextravascular soft tissues.

A separate second, lateral or straight-line access aperture with apenetrable septum enhances the safety of port removal over a wirepreventing inadvertent cutting or dislodgement of the port catheter withresultant intravascular foreign body creation. Identification and saferemoval of the catheter can at times be difficult secondary to abundantadherent surrounding scar tissue. The placement of a needle and then awire through the straight-line-access port and catheter enhances theoperator's ability to palpate and safely dissect around the catheter inorder to remove it, simultaneously lessening the likelihood ofinadvertently transecting the catheter and resulting in an intravascularforeign body. If transection of the catheter were to occur, albeitunlikely because of the traversing wire, the fragment may be retrievablewith an intravascular snare since the wire may be securing it.

A separate lateral or straight-line access aperture (to be enteredparallel to or at a acute angle relative to the port chamber floor) witha penetrable septum enables over-the-wire port exchange for amalfunctioning port thereby increasing the speed and efficiency ofreplacing a malfunctioning port. Typically, port revision requiresstepwise removal of the malfunctioning port and then stepwisereplacement with a new port. Placement of a needle and subsequently awire through the straight-line-access aperture opposite the working endof the port catheter may enable exchange of a malfunctioning port over awire after freeing the existing port from surrounding scar tissue withblunt dissection by one or more incisions. A peel away sheath mayinitially be placed over the wire, facilitating placement of the newport and attached catheter by reducing friction. The initial peel-awaysheath placement also tends to allow time for sizing of the length ofthe new port catheter relative to the length of the old one prior to itsplacement into the venous system, over the wire and through the peelaway sheath.

A double lumen vascular access port in accordance with the presentinvention contains a total of four different needle access points orapertures, specifically two juxtaposed perpendicular-access aperturesfor routine clinical use and two adjoining or adjacentstraight-line-access apertures for remedying port catheter malfunction.A midline vertical or perpendicular septum is provided to divide theinternal chamber of the port body into respective port body chambers. Apalpable ridge or alternatively a depression may be located between twojuxtaposed port septa or diaphragms to facilitate needle placement intothe respective port body chambers by palpation. The two adjacentstraight-line-access apertures, located on the side of the double lumenport body opposite the exiting catheter, allow for the advancement ofvarious devices including but not limited to two wires at preferably ashallow angle (acute angle) or the optimal working angle, namely astraight angle (180 degrees) to enter respective halves of the exitingintravascular catheter which contains a midline septum characteristic ofdouble lumen Portacath design. The straight-line-access aperturesprovide the ideal angle of approach for advancing needles into therespective semicircular or semi-cylindrical outlet apertures, andsubsequently wires or other devices in order to engage or enter theexiting respective halves of the intravascular catheter, located on theport body opposite the straight-line-access apertures in order toperform various intravascular procedures with the goal of restoring orimproving vascular port patency or to perform high flow vascularprocedures such as plasmapheresis or dialysis. The more conical ortapered shapes of the internal surfaces of the respective port bodychambers, separated by a midline septum, opposite the respectivestraight-line-access working apertures, facilitate or help guide theentrance of the two respective straight-line access needles oralternatively wires into the respective outlet apertures, subsequentlygaining access to the two halves of the exiting catheter and thevascular system, under fluoroscopy, for performance of the variousmethods described herein. The straight-line-access apertures, alignedwith the respective outlet apertures, provide the ideal angle ofapproach for needle and or wire advancement, along with wiremanipulation and steerability both before and after entering the exitingcatheter and ultimately within the vascular system.

A special needle design consisting of a semicircular (orsemi-cylindrical) cannula and a semicircular (or semi-cylindrical) yetpointed stylet may be provided in order to directly engage thesemicircular outlet aperture, to enable temporary locking of the cannulato the port body and outlet tube particularly for high-flow procedures.High-flow applications such as apheresis and dialysis require directneedle engagement, coupled with a reversible locking mechanism (no backflow), into the respective halves of the semicircular outlet tubes,necessitating the use of corresponding semicircular cannula andsemicircular pointed inner stylet. A traditional cylindrical cannulawith pointed stylet (Seldinger needle) may be used to direct a wire intoa semicircular outlet aperture (s) without directly seating or lockingthe needle to the outlet aperture, in any low-flow applications such asmaintenance of secondary port patency. Alternatively, to enable use ofconventional cylindrical needle assemblies with a double lumen vascularaccess port in accordance with the present invention, the vascularaccess port may be provided with (1) dual outlet tubes havingcylindrical lumens, (2) a dual-flow outlet tube with a proximal endportion having two cylindrical lumens and a distal end portion havingsemi-cylindrical lumens, and (3) a thickened port body wall having twocylindrical lumens communicating with semi-cylindrical lumens in theoutlet tube.

The port body shape may be configured to optimally accommodate thestraight-line-access apertures and guide the placement of initially aneedle and subsequently various wires, devices, or tools, via theaforementioned straight-line-access aperture or apertures through theport body into the exiting outlet tube and ultimately the intravascularcatheter. For instance, the port body may be wider opposite the exitingcatheter in order to accommodate the placement of one or morestraight-line access apertures. One version of the port may thereforeassume a horseshoe shape with a more tapered or conical end located onthe exiting catheter side and an opposite wider end incorporating thestraight-line-access aperture or apertures. An overall rounded portchamber may passively help guide the needle toward said conical end.Rounding of the edges of the port body along the wider horseshoe-shapedend may reduce friction for easier port placement, removal, or exchange.Alternatively the port body may assume on an outer side an elongated,oval, or teardrop shape in order to reduce friction during port removalor exchange after scar tissue has developed, with traction being placedon the port by means of a clamp. A conical or tapered inner contour ofthe port chamber wall opposite the straight-line-access working apertureor apertures facilitates or helps guide the entrance of the needle orwire into the exiting outlet tube and ultimately a wire into theintravascular catheter and subsequently into the vascular system.

Alternatively, the body of a dual-chamber vascular access port may beconfigured in a more conventional manner with two cylindrical orpreferably oval or round spheroid chambers (true spheres or oblatespheres) separated by a palpable ridgeline since this design fosterscircular motion and mixing of the injected fluids minimizing dead spacewithin the chamber. Acute edges and corners result in sudden directionalchanges in fluid flow through the port chamber, creating dead zones,cell shearing, platelet activation and clotting. Fluoroscopic guidancealone enables placement of an access needle into the rounded orsemicircular straight-line-access port aperture or diaphragm andsubsequently into outlet aperture and outlet tube after traversing theport chamber, then threading a wire into the exiting catheter whilemaintaining the most ergonomic shape for minimizing dead space andactivation of the clotting cascade within the port chamber. The presentdesign does not substantively alter the technique or equipment requiredfor routine clinical dual lumen port access by nurses or otherhealthcare personnel relative to current devices. Therefore there is noneed for new training or new equipment for routine perpendicular-accesspurposes.

In another embodiment of the invention, the double lumen port body or aportion thereof in accordance with the invention is at least partiallyradiopaque while the respective perpendicular-access andstraight-line-access apertures, along with the outlet apertures, areradiolucent thereby facilitating fluoroscopically guided needleplacement through either aperture but particularly withstraight-line-access aperture or apertures, in preparation for variousvascular interventions with the primary goal of maintaining secondaryport patency or for performing high flow procedures such asplasmapheresis or dialysis. For example only the sidewalls of the portbody may be radiopaque or partially radiopaque while both theperpendicular-access apertures and the straight-line access aperturesmay be radiolucent along with the respective outlet apertures. Or thestraight-line-access apertures, perpendicular-access apertures, oroutlet apertures, may have enhanced radiopaque edges to facilitatefluoroscopic needle placement. Alternatively, the double lumen port bodymay be largely radiolucent with complete or partial radiopaque edges orrims provided for the otherwise radiolucent straight-line-accessapertures, perpendicular-access apertures, or outlet apertures, tofacilitate fluoroscopic needle placement. This is an important port bodydesign feature since accessing the straight-line-access aperture(s) maybe more difficult in some cases than the standard perpendicular-accessaperture(s) when using palpation alone and once accessed any procedureto remedy malfunction of the vascular access port may invariably beguided by fluoroscopy, typically performed by a physician such as aradiologist.

Accordingly, an implantable vascular access port may be provided withvarying degrees of radio-opacity or radio-translucency to facilitateaccess under fluoroscopic guidance. Where (i) a major portion of theport body has a first predetermined degree of radio-opacity, (ii) thelateral-access and outlet apertures exhibit a second predetermineddegree of radio-opacity, and (iii) the port body has edge regionsextending about and defining the lateral-access and outlet apertures,the edge regions having a third predetermined degree of radio-opacity,then at least one of the second and the third predetermined degrees ofradio-opacity differs substantially from the first predetermined degreeof radio-opacity. Optionally, the vertical-access aperture may also bedistinguished by the second predetermined degree of radio-opacity or byan edge region of the third predetermined degree of radio-opacity.Radio-opacity may vary between essentially zero (radio-translucence) andessentially 100% (completely radio-opaque). The degrees of radio-opacityare understood as qualitative in that each degree of radio-opacity canlie within a numerical or percentage range but where the degrees differfor enhancing visualization, the respective ranges of radio-opacity donot overlap. Thus the various physical features are fluoroscopicallydistinguishable. It is to be understood that the radio-opacity of alateral access aperture or a top (vertical) access aperture is the sameas, and determined by, the radio-opacity of the associated septum.

In summary a double lumen access port in accordance with the presentinvention contains a total of four different needle access points orapertures, specifically two juxtaposed perpendicular-access aperturesfor routine clinical use and two adjoining straight-line-accessapertures for high flow applications such as plasmapheresis or dialysisas well as maintaining secondary patency enabling all of theaforementioned properties, functions, and methods of the single lumendevice.

In a high-flow vascular access method in accordance with the presentinvention, exemplarily for apheresis or dialysis, one attaches acatheter to a hollow outlet tube of a vascular access port, andextending or deploys the catheter in a central venous system of thepatient. One inserts a distal end portion of a non-coring needleassembly along a straight-line path through a lateral access septum andaperture, across an internal chamber of the access port, and through anoutlet aperture into the hollow outlet tube. One releasably locks acannula of the non-coring needle assembly at least indirectly to thehollow outlet tube and removes a stylet needle from the non-coringneedle assembly after inserting of the distal end portion of thenon-coring needle assembly through the lateral access septum. Thereafterone guides blood at a substantial flow rate from the central venoussystem of the patient through the catheter, the hollow outlet tube, andthe cannula. One conducts an apheresis or dialysis procedure on theblood flowing from the central venous system of the patient through thecatheter, the hollow outlet tube, and the cannula and thereafter returnsthe blood to the vascular system of the patient.

The blood may be returned to the patient's vascular system by directingthe blood via a peripheral or central needle cannulation or a separateimplanted vascular access port. Alternatively, the vascular access portthrough which blood is withdrawn from the patient may be a dual lumenport with both venous access and return capabilities. In the lattercase, the port body of the dual lumen port preferably has (i) at leasttwo internal chambers, (ii) at least two outlet apertures each incommunication with a respective one of the at least two internalchambers, (iii) at least two lateral access apertures each defining arespective straight-line-access path or direction to a respective one ofthe at least two outlet apertures, (iv) at least two top accessapertures each formed in the upper wall and defining a respectiveperpendicular- or vertical-access path or direction substantiallyperpendicular to the upper wall and the lower or floor wall, (v) atleast two first septum coverings closing respective ones of the at leasttwo lateral access apertures, (vi) at least two second septum coveringsclosing respective ones of the at least one top access apertures, and(vii) at least hollow outlet tube passageways in fluid communicationwith respective ones of the at least two internal chambers andrespective ones of the at least two outlet apertures.

A special needle design consisting of a semicircular (orsemi-cylindrical) cannula and a semicircular (or semi-cylindrical) yetpointed stylet may be provided in order to directly engage thesemicircular outlet aperture, to enable temporary locking of the cannulato the port body and outlet tube particularly for high-flow procedures.Again, high-flow applications such as apheresis and dialysis requiredirect needle engagement, coupled with a reversible locking mechanism(no back flow), into the respective halves of conventionallysemicircular outlet tubes. To enable use of conventional cylindricalneedle assemblies with a double lumen vascular access port, the vascularaccess port may be provided with (1) dual outlet tubes havingcylindrical lumens, (2) a dual-flow outlet tube with a proximal endportion having two cylindrical lumens and a distal end portion havingsemi-cylindrical lumens, and (3) a thickened port body wall having twocylindrical lumens communicating with semi-cylindrical lumens in theoutlet tube. Alternatively, a semi-cylindrical stylet-cannula needle maybe used for releasably lockable engagement of the needle cannula with asemicircular outlet-tube lumen.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sagittal cross-section view of an access port apparatusaccording to a prior art design.

FIG. 2 is coronal cross-sectional view of the access port apparatus ofthe access port of FIG. 1 , taken along the line II-II therein, along avertical plane, orthogonal to the plane of FIG. 1 .

FIG. 3 is a sagittal cross-section view of a saucerized or conicalaccess port chamber apparatus according to a prior art design containinga specialized curved pencil point access needle, which in turn containsa distal side hole along the apex of the curved needle.

FIG. 4 is a sagittal cross-section view of a prior art design similar tothat of FIG. 3 , also showing a guide wire being slidably insertedthrough the needle apparatus and into a catheter.

FIG. 5 is a top plan view of an access port apparatus according to aselected illustrative embodiment of the present invention with oneperpendicular-access septum and one straight-line-access septum with anoverall oval shape to the port body.

FIG. 6 is a midline sagittal cross-section view of the access portapparatus of FIG. 5 , taken along the line VI-VI therein.

FIG. 7 is a midline sagittal cross-section view of the access portapparatus of FIG. 5 , with a standard curved Huber needle insertedthrough a perpendicular-access port septum and associated aperture.

FIG. 8 is a midline sagittal cross-section view of the access portapparatus of FIG. 5 , with a straight Huber needle or Seldinger needleinserted through a straight-line-access septum and associated aperture,also showing a guide wire being slidably inserted through the needletoward the opening of a tubular catheter attachment site, whichprotrudes from the port body.

FIG. 9 is a coronal cross-sectional view of the access apparatus in FIG.5 , taken along the line IX-IX therein, along a vertical plane, which isorthogonal to that of FIG. 6 , and showing the directed conical shape ofthe port chamber toward the opening of the tubular catheter attachmentsite.

FIG. 10 is a horizontal cross-sectional view of the access apparatus inFIG. 6 , taken along the line X-X therein, along a horizontal plane,which is orthogonal to that of FIG. 6 .

FIG. 11 is a horizontal cross-sectional view similar to that of FIG. 10, also showing a straight Huber needle or Seldinger needle insertedthrough a horizontal port septum or aperture with a guide wire beingslidably inserted through the needle into an outlet stem or tube andattached single lumen catheter.

FIG. 12 is a top view of a double lumen access port apparatus accordingto a selected illustrative embodiment of the present invention with twoperpendicular-access septa and two straight-line-access septa orapertures with an overall oval or elliptic frusto-conical shape to theport body.

FIG. 13 is a sagittal cross-section view of the access port apparatus ofFIG. 12 , taken along line XIII-XIII in FIG. 15 .

FIG. 14 is a coronal cross-sectional view of the access apparatus ofFIGS. 12 and 13 , taken along the line XIV-XIV in FIG. 12 , along avertical plane, which is orthogonal to the drawing plane of FIG. 13 ,and showing a directed conical shape of the port chamber toward the twosemicircular openings of the double lumen tubular catheter attachmentsite.

FIG. 15 is a horizontal cross-sectional view of the access apparatus ofFIGS. 12-14 , taken along the line XV-XV in FIG. 13 , along a horizontalplane, which is orthogonal to the drawing plane of FIG. 13 , alsoshowing an attached double lumen catheter.

FIG. 16 is a horizontal cross-sectional view similar to that of FIG. 15, also showing two straight Huber needles or Seldinger needles insertedthrough two separate straight-line-access port septa or apertures withguide wires being slidably inserted through the respective needles intothe two halves of a double lumen catheter.

FIG. 17 is a top view of an access port apparatus according to aselected illustrative embodiment of the present invention with oneperpendicular-access septum and one straight-line-access septum with anoverall frusto-conical shape to the port body.

FIG. 18 is a midline sagittal cross-section view of the access portapparatus of FIG. 17 , taken along the line XVIII-XVIII therein.

FIG. 19 is a coronal cross-sectional view of the access apparatus inFIG. 17 , taken along the line XIX-XIX therein, along a vertical plane,which is orthogonal to that of FIG. 18 , and showing the directedconical shape of the port chamber toward the opening of the tubularcatheter attachment site.

FIG. 20 a horizontal cross-sectional view of the access apparatus inFIG. 18 , taken along the line XX-XX therein, along a horizontal plane,which is orthogonal to that of FIG. 18 , also showing an attached singlelumen catheter.

FIG. 21 is a horizontal cross-sectional view similar to that of FIG. 20, also showing a straight Huber needle or Seldinger needle insertedthrough a straight-line-access port septum or aperture with a guide wirebeing slidably inserted through the needle into a single lumen catheter.

FIG. 22 is a diagram of a generic patient's central venous access systemaccording to a prior art design.

FIG. 23 is a diagram of a generic patient's central venous access systemaccording to a prior art design with a biofilm or fibrin sheath coatingthe intravascular portion of the catheter tip.

FIG. 24 is a diagram of a generic patient's central venous access systemaccording to a prior art design, similar to FIG. 23 , showingpositioning of a loop snare over the catheter and fibrin sheath.

FIG. 25 is a diagram of a generic patient's central venous access systemaccording to a prior art design, similar to FIG. 24 , showing theprocedure related complication of a free intravascular catheter fragmentwhich may occur without the inventive device described herein.

FIG. 26 is a diagram of a generic patient's central venous access systemaccording to a prior art design, showing a flipped or malpositionedcatheter.

FIG. 27 is a diagram of a central venous access system in accordancewith the present invention, demonstrating advancement of a loop snareover a wire, placed through the port horizontal septum, in preparationfor fibrin sheath stripping, commensurate with the method describedherein.

FIG. 28 is a diagram of a central venous access system in accordancewith the present invention, similar to FIG. 27 , demonstrating furtheradvancement of a loop snare over a wire, placed through the portstraight-line-access septum, and subsequently over a catheter coatedwith a fibrin sheath, ideally positioned to perform fibrin sheathstripping, commensurate with the method described herein.

FIG. 29 is a diagram of a central venous access system in accordancewith the present invention, similar to FIG. 28 , demonstrating loopsnare removal of a fibrin sheath over a wire, placed through thestraight-line-access port septum, commensurate with the method describedherein.

FIG. 30 is a diagram of a central venous access system in accordancewith the present invention, similar to FIG. 28 , demonstrating how theposition of a broken catheter fragment can be removed in a controlledmanner, over a wire placed through the straight-line-access port septum,preventing the complication of a free intravascular fragment shown inFIG. 25 , commensurate with the method described herein.

FIG. 31 is a diagram of a central venous access system in accordancewith the present invention, showing a flipped catheter tip, and a wirebeing advanced into the straight-line-access port septum in preparationfor catheter repositioning, commensurate with the method describedherein.

FIG. 32 is a diagram of a central venous access system in accordancewith the present invention, similar to FIG. 31 , showing a repositionedcatheter tip performed utilizing a wire placed through thestraight-line-access port septum, with the wire shown exiting from theend of the catheter, commensurate with the method described herein.

FIG. 33 is a diagram of a central venous access system in accordancewith the present invention, similar to FIG. 32 , showing a repositionedcatheter tip performed utilizing a wire placed through thestraight-line-access port septum, with the wire now haven been withdrawnback into the catheter, commensurate with the method described herein.

FIG. 34 is a schematic side elevational view of a non-coring needle andcannula assembly and a cross-sectional view of an outlet tube formedwith cooperating snap-lock fit formations, utilizable in any of thevascular access ports disclosed herein.

FIG. 35 is a schematic side elevational view of another implantablevascular access port in accordance with the present invention withfrusto-conical body and frusto-conical (shown) or cylindrical chamber.

FIG. 36 is a schematic side elevational view of an implantable vascularaccess port similar to that of FIG. 35 , showing an alternative moresuperior or higher positioning of inlet or lateral aperture and outletstem.

FIG. 37 is partially a schematic side-elevational view of a furtherimplantable vascular access port in accordance with the presentinvention, showing a frusto-conical port body and an ovoid or ellipsoidchamber.

FIG. 38 is a schematic side elevational view of an implantable vascularaccess port similar to that of FIG. 37 , showing a tangential outlettube relative to an ovoid or ellipsoid port chamber and aconical-skin-covered external inwardly tapering recess or palpabledepression, forming the lateral access aperture with inner septum.

FIG. 39 is a schematic side elevational view of an implantable vascularaccess port similar to that of FIG. 38 , showing a bent or doubly angledoutlet tube.

FIG. 40 is partially a schematic side-elevational view of yet anotherimplantable vascular access port in accordance with the presentinvention, showing a frusto-conical port body and frusto-conical (shown)or cylindrical chamber and an inferiorly angled outlet stem.

FIG. 41 is a schematic side elevational view of an implantable vascularaccess port similar to that of FIG. 40 , showing a modifiedfrusto-conical port body shape and lateral access aperture with aninferiorly angled outlet stem.

FIG. 42 is a schematic side elevational view of an implantable vascularaccess port similar to that of FIG. 41 , showing an ellipsoidal internalchamber with an inferiorly angled outlet stem.

FIG. 43 is a schematic side elevational view of an implantable vascularaccess port body similar to that of FIG. 42 , showing a tangentialoutlet stem and access aperture relative to an ellipsoidal port chamberwith an inferiorly angled outlet stem.

FIG. 44 is a schematic horizontal cross-sectional view of anotherimplantable dual-chamber vascular access port in accordance with thepresent invention.

FIG. 45 is a detail of FIG. 44 , on a larger scale, showing annularbeads inside respective passageways in a port body wall, for reversiblylocking a stylet needle cannula to the port body to enable fluidcommunication between the passageways and respective channels in adual-flow outlet tube.

FIG. 46 is a schematic perspective view of a generic vascular accessport in accordance with the present invention, showing areas ofdifferent degrees of radio-opacity or -translucence to facilitate useunder fluoroscopic guidance.

FIG. 47 is a schematic partial cross-sectional view of a dual chambervascular access port with dual outlet tubes, pursuant to the presentinvention.

FIG. 48 is a diagram of an outlet tube for a dual chamber vascularaccess port, showing two lumens each with a distal end having a D-shapedcross-section (semi-cylindrical) and a proximal end with a circularcross-section.

DETAILED DESCRIPTION

As used herein the terms “perpendicular-access” and“straight-line-access” refer to respective angles of placement orinsertion of a needle through a skin surface into a vascular access portimplanted beneath that skin surface. The term “perpendicular-access”signifies a direction of needle placement or insertion that issubstantially, or at least mostly, perpendicular to a floor surface ofan internal chamber of the access port as well as the skin overlying theperpendicular-access septum of the port (in contradistinction to theskin covering sidewalls of the port which may be sloped or angled). Aperpendicular-access aperture in a port body as described herein iscovered by a penetrable flexible septum located close to the skinsurface for routine clinical access. Concomitantly, aperpendicular-access aperture is located in an upper surface of animplantable vascular port, next to the skin surface, and may be termed a“top access aperture.”

Ideally, a perpendicular-access needle insertion line or direction isoriented 90° relative to the floor surface of a port body internalchamber or the lower wall of the port body. However, in practice theneedle insertion direction may deviate from 90° by an angle of 10° to20° from the exact perpendicularity.

Concomitantly the term “straight-line access” signifies a direction ofneedle placement or insertion that is at least partially parallel to thefloor or lower wall of the implanted vascular access port, or inclinedwith respect to that floor or lower wall preferably at an angle of lessthan about 40° but possibly up to about 70°. The port sidewall, as wellas the skin covering the port sidewall, may be sloped, or angledrelative to the floor of the port body. A straight-line-access apertureis configured for placement or penetration of a needle preferably inparallel with, or in near parallel relation to, the (preferably flat)port floor. However, a straight-line access path, exemplarily forhigh-flow-rate access applications such as apheresis and dialysis, maybe inclined by an angle of up to about 70° relative to the lower wall ofthe port body. The straight-line access path is collinear with theoutlet tube on the opposite side of the port body to facilitatetrans-chamber needle engagement in the outlet tube. The outlet tube orthe port body is provided with a reversible needle locking mechanism forthe performance of the high flow procedures such as apheresis anddialysis as well as stable needle positioning for the performance ofother methods described herein.

A vascular access “port body” is contemplated herein to denote a housingor casing made of a material resistant to penetration by a medicalneedle. The body of a vascular access port is provided with openings orapertures through which a needle may be inserted. A “lateral accessaperture” or “straight-line access aperture” is used herein to denote anopening so positioned in a port body as to enable a straight-line accessto the outlet tube on the opposite side of the port chamber. While alateral access port is typically disposed in a sidewall of a port body,the word “lateral” as used herein denotes an access port or aperture asbeing “to the side” of a routine-maintenance access port in a top orupper wall of a vascular access port body. Accordingly a lateral accessport may be located in the upper wall of a vascular access port body,laterally of a main or routine access aperture. However, it iscontemplated that a lateral access port, to effectively facilitatecertain applications, such as high-flow venous access for dialysis andapheresis defines a straight-line access path oriented between 0 andabout 70 degrees from the horizontal lower wall of the port body andconcomitantly the floor surface of the pertinent internal chamber,collinear with the outlet tube on the opposite side of he port chamber.

A “lateral access aperture” or “straight-line access aperture” in a portbody as described herein is covered by a penetrable flexible septumlocated close to the skin surface for enabling fluoroscopicrepositioning of a previously placed, undesirably migrated intravascularport and/or an associated catheter tip by advancement of a needlethrough the lateral sidewall- or straight-line-access aperture, thenthrough said port body, into the outlet stem, and subsequently advancinga steerable wire through the needle into an attached catheter underfluoroscopy.

The term “outwardly tapering chamber extension” is used herein to denotea recess or ancillary cavity within a port body that communicates on aninner side with a main internal port chamber and that forms an outletaperture communicating with an outlet tube configured to extend into avein of a patient upon implantation or deployment of the associatedvascular access port into a patient. The outlet aperture may be definedas the entirety of the recess or ancillary cavity between the internalchamber proper and the outlet tube or may be limited, in thealternative, to one plane, such as the upstream end or the downstreamend of the recess or cavity. In the present disclosure, it is the lastalternative that is generally contemplated.

The term “inwardly tapering recess” is used herein to denote adepression, concavity, or recess extending through a port body from anouter surface thereof to an internal cavity of the port body. Thedepression, concavity, or recess has a transverse dimension (width,diameter) that is less on the inner side than the outer side. Thedepression, concavity, or recess may be hemispherical, ovoid,elliptical, hyperbolic, etc., and have a concomitantly circularcross-section or may be pyramidal with a polygonal cross-section. Othertapering geometries may be utilized as well. The inwardly taperingrecess within the port body typically comprises the lateral accessaperture, provided at an inner end with a self-sealing septum ormembrane for needle penetration at its junction with the inner chamberwall.

The word “needle” and the term “needle assembly” as used herein withreference to high-flow vascular access applications such as apheresisand dialysis denotes a non-coring access needle assembly comprising anouter cannula and a sharp inner stylet traversing a longitudinal lumenof the cannula. The cannula and corresponding pointed inner stylet canbe either cylindrical or semi-cylindrical (with a D-shaped transversecross-section) depending on the shape of the lumen of the correspondingoutlet tube. A semi-cylindrical cannula and stylet shape is required forone double lumen port described herein (see, e.g., FIG. 15 ) while acylindrical needle may be utilized for the various single lumen versionsand another double lumen embodiment with outwardly angled lateral accessapertures (see FIG. 44 ). The stylet and cannula are preferably made ofa metal or alloy material. The cannula is formed proximate a distal endwith an annular groove or one or more beads, optionally annular, forcooperating in a reversible snap-lock fit with a resilient bead orgroove projecting from an inner surface of an outlet tube or of atubular passageway inside the wall of a port body of an implantablevascular access port as described herein. The stylet is used to puncturea self-sealing membrane or septum and is removed from the cannula oncethe cannula is releasably locked to an outlet tube or port bodypassageway.

A port body of a vascular access port as described herein is preferablymade for the most part of an at least partially radio-opaque material.Ideally the material is not completely opaque so as to enablevisualization of the internal chamber and a needle's progress throughthe chamber toward the outlet aperture during a vascular accessprocedure. The port body may have small portions, for instance, alongedge regions surrounding the lateral access, top access, and outletapertures, which have a perceptibly different radio-opacity than themain portion of the port body to facilitate visual detection of theapertures and septa during access procedures. Typically, but notnecessarily, the septa are made of a radiolucent material. In anotherversion the port body of a vascular access port as described herein ispreferably made for the most part of a radiolucent material so as toenable visualization of a needle's progress through the chamber towardthe outlet aperture during a vascular access procedure. The edgessurrounding the lateral access, top access, and outlet apertures, ofsaid radiolucent port body are at least partially radiopaque. Typicallyagain, but not necessarily, the septa are made of a radiolucentmaterial.

An implantable vascular port apparatus or device 52 as depicted in FIGS.5-11 includes a main port body 56 having an internal chamber 54 formedtherein. The main port body 56 may have various shapes including but notlimited to frusto-conical, elliptic frusto-conical, teardrop shaped,torpedo shaped, horseshoe shaped, and ovoid. The port body 56 and portchamber 54 may be of similar or differing shapes respectively. Possiblechamber shapes include but are not limited to cylindrical,frusto-conical, elliptic frusto-conical, ellipsoidal, and spheroidal.FIGS. 5-11 depict an elliptic frusto-conical port body 56 and portchamber 54. The main port body 56 has two penetrable septa 58 and 60extending across and closing respective apertures 158 and 160: aperpendicular- or top-access septum 58 in aperture 158 similar toconventional ports as well as a novel straight-line- or lateralsidewall-access septum 60 in aperture 160 primary for the performance ofvarious interventions to facilitate initial port placement, portcatheter repositioning, maintenance of secondary port patency, portremoval, high-flow applications, and port exchange. The radiolucentsepta 58 and 60 are formed from a resiliently deformable material suchas silicone elastomer. The perpendicular- or top-access andstraight-line- or lateral sidewall-access septa 58 and 60 each include arespective thickened central portion 41 a and 41 b as shown in FIGS. 6-9and a thinner edge portion or flange 43 a and 43 a for placement in arespective circumferential channel or groove 45 a and 45 b, to anchorthe septa in place in the main port body 56. The main port body 56 isformed from a biocompatible material, such as titanium alloy or otherbiocompatible corrosion-resistant metal, or from a biocompatibleplastic. A titanium liner may be used along a floor or bottom surface 62of the port chamber 54 when plastic is utilized for the port body 56.

In one version of an implantable vascular access port, the port body 56and port chamber 54 are wider on the side containing thestraight-line-access septum 60 in order to accommodate it and facilitateneedle placement from various angles of approach, in contradistinctionto an opposite side of port body 56 containing a hollow outlet tube 64,which may be more narrow or tapered. A sufficiently widestraight-line-access port aperture may also be formed in a standardfrusto-conical port body without the need for widening the side of theport containing the straight-line-access aperture.

The straight-line- or lateral sidewall-access aperture 160 may be ofvarious shapes and sizes assuming a round, oval, or rectangularconfiguration for example; if the port body and chamber assumes afrusto-conical configuration the straight-line-access aperture isslanted or curved. A wider straight-line-access aperture may allow foreasier needle placement from different needle skin puncture locationsand angles of approach. In another version the straight-line-accessaperture 160 may be narrower and therefore less dependent on port bodyshape, allowing for precise alignment of the straight-line-access septum60 with a port chamber outlet aperture 66. A narrowerstraight-line-access aperture 160 may be more difficult to target orenter but can be precisely aligned with the exiting port chamber outletaperture 66, facilitating placement of a straight-line-access needle 72and subsequently a slidable wire 74 through it, into the outlet aperture66 and an attached catheter 70.

In one version the port body is relatively radiopaque while therespective silicone covered top access and lateral sidewall aperturesare radiolucent. The edges of the at least partially radiopaque portbody 56 surrounding a more narrow precisely aligned radiolucentstraight-line- or lateral sidewall-access aperture 160 may be made evenmore radiopaque than the port body in order to better guide placement ofthe access needle through the straight-line-access septum 60 underdirect fluoroscopic guidance; this modification may be of valueregardless of aperture size. The disadvantage of accessing a smallstraight-line-access aperture 160 may therefore be overcome with the useof accentuated radiopaque port body markers along it edges, therebyenabling fluoroscopic needle placement while at the same time exploitingthe advantage of more precise alignment of the straight-line-accessaperture 160 with the port chamber outlet aperture 66. Outlet aperture66 is configured to be radiolucent similarly to the respective accessapertures to facilitate fluoroscopic cannulation with a needle or wire;similarly the outlet aperture 66 may have accentuated, at leastpartially radiopaque, rims or edges for needle guidance. In anotherversion the port body is radiolucent with radiopaque edges or rims alongthe similarly radiolucent top and lateral sidewall access aperturesalong with the outlet aperture, thereby similarly guiding needleplacement under fluoroscopy into or through any of the aforementionedapertures. The port chamber outlet aperture 66 may be surrounded by aninner surface of the internal chamber 54 having a straight conical orfunnel-like shape and defining an outwardly tapering chamber extension(as opposed to a curved funnel) to help facilitate the placement of aslidable wire 74 through a straight access needle 72 placed through thestraight-line-access septum 60, to facilitate entrance of the wire 74into the hollow outlet tube 64 and subsequently the proximal catheter 70(FIGS. 8-11 ). Alternatively the needle may directly engage a channel inthe port body 56 adjacent to the outlet aperture 66 or the outlet stem64 prior to wire advancement.

The straight conical outlet aperture or outwardly tapering chamberextension 66 shown in FIGS. 6-9 is located flush with the floor orbottom surface 62 of the internal chamber 54 of port body 56.Alternatively the straight conical chamber outlet aperture 66 may becentered at a midpoint between a top or upper surface 68 and the flooror bottom surface 62 of the port chamber 54 or anywhere in between, itsprecise location being preferably aligned with the location of thestraight-line- or lateral sidewall-access aperture 160. Theperpendicular-access aperture 158 for routine clinical use is shown inFIG. 7 with a curved Huber access needle in place for injectingmedicines, into the internal port chamber 54, the medicines then passingthrough the port chamber outlet aperture 66, the hollow outlet tube 64,and finally the proximal catheter 70. The main port body 56 may have oneor more round or oval eyelets 78 formed along its margins, particularlyalong a peripheral or circumferentially extending foot 79, to allowsuturing of the port apparatus 52 to the underlying soft tissues withina surgically created subcutaneous pocket. These eyelets 78 may or maynot be filled with silicone elastomeric material.

In a double lumen implantable vascular access port 252 (FIGS. 12-16 )two internal port chambers 254 are separated by a midline divider orpartition 282 and exhibit respective perpendicular- or top-accessapertures 258 and respective straight-line-access or lateral sidewallapertures 260. The port 252 includes a main port body 256 that iselliptic frusto-conical in configuration in one version and has fourpenetrable septa, namely two perpendicular-access septa 258′ overrespective apertures 258, similar to conventional double ports, as wellas two straight-line-access or lateral sidewall septa 260′ overrespective apertures 260, primarily for the performance of variousinterventions to facilitate port placement, port repositioning,maintenance of secondary port patency, port removal, and port exchange.The septa (258′ and 260′) are formed from a resiliently deformablematerial such as silicone elastomer. The construction of the respectiveperpendicular- and straight-line-access septa (258′ and 260′) mayinclude a thickened central portion 241 as shown in FIGS. 13 and 14 anda thinner edge portion 243 for placement in a circumferential channel orgroove 245, to anchor the septa in place in the main port body 256. Themain port body 256 is formed from a biocompatible material, such astitanium alloy or other biocompatible corrosion-resistant metal, or froma biocompatible plastic. A titanium liner (not separately depicted) maybe used along floors or bottom surfaces 262 of the port chambers 254when plastic is utilized for the port body 256.

The straight-line-access apertures 260 may be of various shapes andsizes assuming a round, oval, or rectangular configuration for example;if the port body 256 and chambers 254 assume an elliptic frusto-conicalconfiguration, external and internal body surfaces not separatelylabeled have a surface curvature along multiple dimensions. Wherestraight-line-access apertures 260 and associated septa 260′ areprovided with a larger width (parallel to the floor or bottom surfaces262), easier needle placement from different angles of approach ispossible. In another version of the double lumen implantable vascularaccess port 252, the straight-line-access apertures 260 may be narrowerand therefore relatively independent of port body shape, allowing formore precise alignment of the straight-line-access apertures 260 withrespective port chamber outlet apertures 266. Narrower parallel-accessapertures 260 are more difficult to target or enter but may be preciselyaligned in the horizontal and or vertical planes with the exiting portchamber semicircular outlet apertures 266, facilitating placement ofstraight-line-access needles 272 and subsequently slidable wires 274into the semicircular outlet apertures 266, and into the respectivesides of an attached double lumen catheter 284, having a midline divideror partition 253. Alternatively the needles 272 may directly engage theoutlet apertures 266 prior to wire advancement. A special needle designconsisting of a semicircular or D shaped cannula and a semicircular yetpointed stylet may be required in order to directly engage thesemicircular outlet aperture 266. A traditional rounded cannula withpointed stylet (Seldinger needle) may likely be adequate to direct awire into the outlet aperture (s) without directly seating the needleinto the semicircular outlet aperture. High flow applications such asapheresis and dialysis require direct needle engagement, coupled with areversible locking mechanism (no back flow), into the respective halvesof the semicircular outlet tubes, necessitating the use of correspondingsemicircular cannula and semicircular pointed inner stylet.

The edges (not separately designated) of the radiopaque port body 256surrounding more narrow precisely aligned straight-line radiolucentaccess apertures 260 may be made more radiopaque than the port body 256in order to better enable placement of the access needles 272 throughthe straight-line-access septa 260′ under direct fluoroscopic guidance,this modification being of value regardless of aperture size. Thedisadvantage of accessing a small straight-line-access aperture 260 maytherefore be overcome with the use of accentuated radiopaque port bodymarkers along the otherwise radiolucent aperture edges, thereby enablingfluoroscopic needle placement while at the same time exploiting theadvantage of precise alignment of the straight-line-access apertures 260with the port chamber outlet apertures 266. The radiopaque midlinedivider or partition 282 of the double lumen port apparatus 252 helpsguide access needles 272 during placement through the two respectivestraight-line-access apertures 260 by fluoroscopy as well as by apalpable subcutaneous ridge 283 formed by the upper edge of the midlinedivider/partition 282 (FIGS. 12, 15, and 16 ).

Insertions or deployments of the straight-line-access needles 272adjacent to respective sides of the midline divider 282 simultaneouslyalign the straight-line-access needles with the respective semicircularoutlet apertures 266 (FIGS. 15 and 16 ). A special needle design (notshown) consisting of a semi-cylindrical cannula and semi-cylindricalpointed stylet may be used to directly engage the semicircular outletaperture, to enable temporary locking of the cannula to the port bodyand outlet tube particularly for high-flow procedures. High-flowapplications such as apheresis and dialysis require direct needleengagement, coupled with a reversible locking mechanism (no back flow),into the respective halves of the semicircular outlet tubes,necessitating the use of corresponding semicircular cannula andsemicircular pointed inner stylet.

Alternatively, to enable use of conventional cylindrical needleassemblies with a double lumen vascular access port in accordance withthe present invention, the vascular access port may be provided with (1)dual outlet tubes having cylindrical lumens, as discussed hereinafterwith reference to FIG. 47 , (2) a dual-flow outlet tube with a proximalend portion having two cylindrical lumens and a distal end portionhaving semi-cylindrical lumens, as described below with reference toFIG. 48 , and (3) a thickened port body wall 277 (FIG. 15 ) having twocylindrical lumens 281 and 283 communicating with semi-cylindricallumens 263 in outlet tube 264. Cylindrical lumens 281 and 283 areprovided with annular snap-lock beads, as discussed herein, forreleasably retaining stylet-needle cannulas particularly for high-flowprocedures. Cylindrical lumens 281 and 283 may have proximal portionsthat extend parallel to partition 282 to facilitate the receiving ofneedle assemblies. Alternatively, straight-line or lateral accessapertures 260 may be disposed at greater distances from partition 282,as shown in FIG. 44 , to enable proper co-linear insertion of needlesinto lumens 281 and 283.

Port chamber outlet apertures 266 may be radiolucent in an otherwise atleast partially radiopaque port body to facilitate needle or wirecannulation. Alternatively the outlet apertures 266 may be provided withradiopaque edges in an otherwise radiolucent port body in order tofacilitate cannulation with a needle or wire. The port chamber outletapertures 266 may be provided with respective straight conical orfunnel-like guiding surfaces (defining outwardly tapering chamberextensions) on the respective downstream sides of internal chambers 254(half or partial funnel in double lumen version on either side of themidline divider 282) to help facilitate the placement of slidable wires274 through straight access needles (either cylindrical orsemi-cylindrical) 272 placed through the straight-line-access septa260′, to facilitate entrance of the wires 274 or needles of semicircularcross-sections 272 into respective lumens 263 of a double lumen hollowoutlet tube 264 and subsequently into respective halves 285 of aproximal double lumen catheter 284, compartmentalized by the midlinecatheter divider 253. (FIG. 16 ). The straight conical outlet aperturesor outwardly tapering chamber extension 266 (half or partial funnel indouble lumen version on either side of the midline divider/partition282) shown in FIGS. 13 and 14 are located flush with the floors 262 ofthe port chambers 254. Alternatively the straight conical chamber outletapertures 266 may be centered at a midpoint between top or uppersurfaces 268 and the floor or bottom surfaces 262 of the port chambers254 or anywhere in between, the precise locations being preferablyaligned with the locations of the straight-line-access apertures 260.The respective perpendicular-access apertures 258 for routine clinicaluse are accessed with a curved Huber needle (shown in FIG. 7 for asingle lumen port) for injecting medicines, which may then enter theport chambers 254, then the port chamber outlet apertures 266,subsequently entering the respective side of the double lumen hollowoutlet tube 264, and finally the respective halves of the proximaldouble lumen catheter 284, separated by the midline divider/partition253. The double lumen outlet tube 264 contains a midline groove 251,which accepts the midline divider 253 of the double lumen catheter 284(FIGS. 12, 15 , and 16). The main port body 256 may have one or moreround or oval eyelets 278 formed at spaced locations in an outwardly andcircumferentially extending foot 279 to allow suturing of the doublelumen implantable vascular access port 252 to the underlying softtissues within a surgically created subcutaneous pocket. These eyelets278 may or may not be filled with silicone elastomeric material.

Another single lumen implantable vascular access port apparatus 352,shown in FIGS. 17-21 includes a main port body 356 having a hollowchamber 354 formed therein. A main port body 356 has two penetrableapertures (358 and 360) including a perpendicular- or top-accessaperture 358 and a straight-line- or lateral-access aperture 360 coveredor bridged by respective septa 358′ and 360′. Perpendicular-accessaperture 358 allows conventional port access while novelstraight-line-access aperture 360 enables or facilitates performance ofvarious interventions to facilitate initial port placement, portcatheter repositioning, maintenance of secondary port patency, portremoval, and port exchange. In this implantable vascular access portapparatus 352, the main port body 356 is frusto-conical, the main portchamber 354 is cylindrical, frusto-conical or preferably ellipsoidal, anellipsoidal or spheroidal port chamber design fosters circular motionand mixing of the injected fluids minimizing dead space within thechamber. Acute edges and corners result in sudden directional changes influid flow through the port chamber creating dead zones, cell shearing,platelet activation and clotting. A frusto-conical body 356 may surrounda cylindrical, frusto-conical or preferably ellipsoidal port chamber 354as shown in FIG. 17 , however, the port body 356 may assume differingshapes including but not limited to a frusto-conical, ellipticfrusto-conical, horseshoe shaped, teardrop shaped, torpedo shaped, orovoid to reduce friction during port exchange, one of the envisionedmethods or procedures made possible by the invention, yet retain thedesirable non-turbulent flow characteristics of an ellipsoidal orspheroid (true sphere or oblate sphere) port chamber 354 (not shown). Inanother version the radiolucent lateral access aperture 360′ isconstructed of an inwardly tapering recess or palpable depression in theport body, allowing for access needle placement into thestraight-line-access septum, which may no longer be located along theperiphery of the port body 356, but more centrally abutting the portchamber (not shown). The port chamber 354 and port body 356 thereforemay be of similar or differing shapes respectively. The septa (358′ and360′) are formed from a resiliently deformable material such as siliconeelastomer. The perpendicular- and straight-line-access septa 358′ and360′ include thickened central portions 341 and 342 as shown in FIGS. 18and 19 and thinner edge portions 343 and 344 for placement incircumferential channels or grooves 345 and 346 to anchor the septa 358′and 360′ in place in the main port body 356. The main port body 356 isformed from a biocompatible material, such as titanium alloy or otherbiocompatible corrosion-resistant metal, or from a biocompatibleplastic. A titanium liner (not shown) may be used along a floor orbottom 362 of the port chamber 354 when plastic is utilized for the portbody 356. The straight-line-access aperture 360 may be of various shapesand sizes assuming a round, oval, or rectangular configuration forexample; in a frusto-conical implantable vascular access apparatus 352the straight-line-access septum 360′ is in part curved FIGS. 17 and 20 .A wider straight-line-access aperture may allow for easier needleplacement from different skin puncture site locations and angles ofapproach. In another version the straight-line-access port aperture 360may be narrower and therefore less dependent on port body shape,allowing for precise alignment of the straight-line-access port septum360′ with the port chamber outlet aperture 366. A narrowerstraight-line-access aperture 360 may be more difficult to target orenter but can be precisely aligned in the horizontal and or verticalplanes with the exiting port chamber outlet aperture 366, facilitatingplacement of a straight-line-access needle 372 and subsequently aslidable wire 374 there through, into the outlet aperture 366, outletstem 364, and an attached catheter 370 (FIG. 21 ). The edges of theradiopaque port body 356 surrounding a more narrow precisely alignedstraight-line-access aperture 360 may be made even more radiopaque thanthe port body 354 in order to better enable placement of the accessneedle into and through the straight-line-access septum 360′ underdirect fluoroscopic guidance, this modification being beneficialregardless of aperture size. The disadvantage of accessing a smallstraight-line-access aperture 360 may therefore be overcome with the useof accentuated radiopaque port body markers along the edges of theaperture, thereby enabling fluoroscopic needle placement while at thesame time exploiting the advantage of more precise alignment of thestraight-line-access aperture 360 with the port chamber outlet aperture366. The port chamber outlet aperture 366 may be located in a straightconical or funnel-like shape or outwardly tapering chamber extension (asopposed to a curved funnel) of the respective wall of the internalchamber 354 to help facilitate the placement of the slidable wire 374through the straight access needle 372 as placed through thestraight-line-access septum 360′, to facilitate entrance of the needle372 or wire 374 into the hollow outlet tube 364 and subsequently theproximal catheter 370 (FIGS. 19-21 ). Alternatively, the needle maydirectly engage a channel in the port body 356 adjacent to the outletaperture 366 or the outlet stem prior to wire advancement. The straightconical outlet aperture (outwardly tapering chamber extension) 366 shownin FIGS. 19-21 is located flush with the floor or bottom surface 362 ofthe port chamber 354. Alternatively the straight conical chamber outletaperture 366 may be centered at the midpoint between a top surface 368and the floor surface 362 of the port chamber 354 or anywhere inbetween, its precise location preferably being aligned with thehorizon-access aperture 360. The perpendicular-access aperture 358, forroutine clinical use, is shown in FIG. 7 with a curved Huber accessneedle in place for injecting medicines, which may then enter the portchamber 354, then the port chamber outlet aperture 366, subsequently thehollow outlet tube 364, and finally the proximal catheter 370. The mainport body 356 may have one or more round or oval eyelets 378 formedalong its margins, particularly, along an outwardly andcircumferentially extending foot 379, to allow suturing of the port orvascular access apparatus 352 to the underlying soft tissues within asurgically created subcutaneous pocket. These eyelets 378 may or may notbe filled with silicone elastomeric material.

A generic port apparatus 20 such as that illustrated in FIGS. 1 and 2 isshown in FIG. 22 surgically implanted into the subcutaneous soft tissuesof the upper chest wall with the proximal catheter attached to the portbody 22, the catheter 36 is shown entering right the internal jugularvein 88, with the distal tip of the catheter 36 positioned in thecentral venous system, either the superior vena cava (SVC) or the rightatrium (RA). FIG. 23 , similar to FIG. 22 , shows a generic portapparatus 20, with a fibrin sheath 90 or biofilm surrounding the distalintravascular portion of the catheter 36, resulting in cathetermalfunction, either complete catheter occlusion or at a minimum aninability to aspirate blood from the catheter, precluding ones abilityto confirm appropriate needle position within the port chamber, and thussafe conditions for the instillation of fluids or medicine. FIG. 24 ,similar to FIG. 23 , shows a generic port apparatus 20, with a fibrinsheath 90 or biofilm surrounding the distal intravascular portion of thecatheter 36, resulting in catheter malfunction. An intravascular loopsnare 92 exiting from a catheter 94 placed from a femoral vein punctureis shown surrounding the port catheter 36 and fibrin sheath 90,immediately prior to tightening the snare in preparation for stripingoff the fibrin sheath from the catheter, an established procedure in themedical field. FIG. 25 , similar to FIG. 24 , shows a generic portapparatus 20, after fibrin sheath stripping with a loop snare 92demonstrating a known complication of such a procedure, which iscatheter fragmentation with a resultant intravascular loose body 96.FIG. 26 , similar to FIG. 22 , shows a generic port apparatus 20, with acatheter 36 having a flipped or migrated aberrant catheter tip in theinternal jugular vein, resulting in catheter dysfunction and anundesirable location to inject medicines, also predisposing to venousthrombosis, a known complication of central venous ports. This aberrantcatheter position can be remedied by snaring the distal end of thecatheter in a similar fashion to that of FIG. 24 for fibrin sheathformation, thereby repositioning the catheter tip in the superior venacava or right atrium; alternatively the port may be surgically revised.

FIG. 27 shows an improved fibrin sheath stripping procedure according tothe present invention, utilizing the vascular port apparatus 52described above with reference to FIGS. 5-11 . The main port body 56 hastwo penetrable septa 58 and 60 covering respective apertures 158 and160, with perpendicular-access septum or aperture 58 similar to that ofconventional ports and with straight-line-access septum 60 primarily forthe performance of various interventions to facilitate initial portplacement, maintenance of secondary port patency, port removal, and portexchange. A slidable wire such as a polytetrafluoroethylene-coated guidewire, sold by the Terumo medical corporation under the trademark“GLIDEWIRE” or other suitable wire is inserted through a straight Huberneedle or Seldinger needle via the straight-line-access port aperture160, through the catheter 36 in order to secure the fibrin sheath 90 andhelp prevent catheter fragmentation from fibrin sheath stripping. Anintravascular loop snare 92 exiting from a catheter 94 placed from afemoral vein puncture is shown surrounding the wire 74 in preparationfor striping off the fibrin sheath from the catheter. FIG. 28 , similarto FIG. 27 , shows the port apparatus 52 in accordance with the presentinvention, with a fibrin sheath 90 or biofilm surrounding the distalintravascular portion of the catheter 36, resulting in cathetermalfunction. An intravascular loop snare 92 exiting from a catheter 94placed from a femoral vein puncture is shown surrounding the portcatheter 36 and fibrin sheath 90, immediately prior to tightening thesnare in preparation for striping off the fibrin sheath from thecatheter 36. FIG. 29 , similar to FIG. 28 , shows subsequent saferemoval of the fibrin sheath 90, with reduced risk of catheterfragmentation, from the port catheter 36 with the loop snare 92, overthe wire 74 placed via the straight-line-access aperture 60. FIG. 30 ,similar to FIG. 29 , shows safe removal of a catheter fragment 96 via aloop snare 92, since the fragment is secured on the wire 74 placedthrough the straight-line-access aperture 160, a known complication offibrin sheath stripping, pursuit to the current invention. The catheterfragment 96 can then be safely removed after it is snared on the wirevia the femoral vein access site trough a vascular sheath.

FIG. 31 shows a port apparatus 52 pursuant to the current invention witha flipped or migrated aberrant catheter tip in the internal jugular vein88, resulting in catheter dysfunction and an undesirable location toinject medicines, also predisposing to venous thrombosis, a knowncomplication of central venous ports. A wire 74 is shown being placedinto the straight-line-access port aperture 60 into the port catheter 36prior to exiting the distal end of the catheter. The aberrant catheterposition can be remedied by advancing a slidable wire 74 through thecatheter, thereby repositioning it in the superior vena cava or rightatrium, in accordance with the invention described herein as shown inFIG. 32 .

A wire placed through the straight-line-access aperture and subsequentlythe catheter as shown in FIG. 32 may be used to dislodge intraluminalblockages or thrombus in order to restore catheter patency. FIG. 33 ,similar to FIG. 32 , shows partial wire withdrawal after catheterrecanalization or dislodgement of the intraluminal thrombus from thecatheter. FIG. 32 also demonstrates how various tools such as amicrobrush or microballon may be advanced through the port apparatus inorder to disrupt and dislodge an attached fibrin sheath or thrombus asan alternative procedure and method to that described for FIGS. 27-30 .

A wire 74 placed through the straight-line-access aperture 60 andsubsequently the catheter 36 as shown in FIG. 32 may facilitate initialcatheter 36 placement into the central venous system, particularly iffriction or kinking is encountered during catheter 36 advancementthrough a peel-away sheath, that is typically used in order to advancethe catheter into the central venous system. Wire advancement may alsobe beneficial if a redundant loop of catheter develops in thesubcutaneous tissues, after initial catheter 36 placement and peel awaysheath removal, with only a small portion of the catheter in the venoussystem, thereby securing the catheter 36 in the venous system andincreasing catheter 36 pushability such that the loop can be eliminated.

FIG. 32 also demonstrate how wire 74 advancement may help preventinadvertent transection of the catheter during port removal increasingones ability to palpate the catheter in order to avoid cutting it, alsopreventing complete transection by its presence within the catheterlumen; in the unlikely event of a complete transection the loosefragment may be secured on the wire allowing fragment 96 retrieval asdemonstrated in FIG. 30 .

FIG. 32 also demonstrates how placement of a long enough wire throughthe straight-line-access aperture through the catheter into the centralvenous system may allow for exchange of a malfunctioning port apparatus52, after making an incision in the skin and freeing it from anysurrounding scar tissue, for a new assembled vascular port apparatus 52of a similar length over the wire. Exchange of a malfunctioning portapparatus 52 over a wire may require an incision near thestraight-line-access aperture incorporating the access needle 72 (FIG.21 ) and may be facilitated by peel-away sheath placement into thesubcutaneous port pocket and catheter tunnel over the wire, afterremoval of the original malfunctioning port apparatus 52, therebyreducing friction for placement of the new port apparatus 52. The portapparatus may be exchanged for a like Portacath apparatus 52 or a newtunneled vascular apparatus such as a Hickman catheter or plasmapheresiscatheter.

FIG. 34 depicts a large-bore (19 to 14 gauge) non-coring needle assembly466, either circular or semi-circular in transverse cross-section, forhigh flow access applications, for instance, for apheresis or dialysis,together with a hollow outlet tube 464 (either round or semicircular incross-section) that may serve as the hollow outlet tube in any ofvarious single (round outlet tube) or dual access (semicircular or roundoutlet tube lumen) implantable vascular ports described herein, such asoutlet tubes 64, 264, 364, 522, 534, 538, 550, 582, 600. Non-coringaccess needle assembly (round or semicircular) 466 may comprise a sharpinner stylet 466 a with an outer cannula 466 b, stylet 466 a traversinga longitudinal lumen 466 c of the cannula. Outlet port or stem 464 isprovided along an inner surface with at least one annular bead or ridge468 that inserts into an annular groove or indentation 470 in an outersurface 472 of cannula 466 b to lock the cannula to the outlet port inhigh flow applications. Bead 468 and groove 470 form a snap-lock fitthat anchors cannula 466 b in place and additionally provides tactileresistive and or vibratory feedback to the operator during a deploymentor coupling procedure; the operator can sense in part through sound andin part through resistance to further forward motion or retraction, thatbead 468 is seated in groove 470. A reversible snap-lock mechanism suchas bead 468 and groove 470 may therefore minimize or eliminate the needfor fluoroscopic guidance during horizontal or lateral access orstraight-line access needle placement (0 to 70 degrees relative to theport floor). Seating of cannula 466 b at the desired location within thelength of outlet tube 464 is facilitated by the tactile, vibratory, andauditory feedback generated by the snap-fit mechanism. Different sizeannular beads or ridges (e.g., of different heights) may be staggeredalong the length of the outlet tube 464, from small (proximal) to big(distal), to accommodate and form a tight fit around more than one sizeneedle diameter, anchoring or engaging a larger gauge needle moreproximally in the outlet tube and smaller diameter needles moredistally, most applicable in an outlet tube of a uniform or nearlyuniform diameter throughout its length. Alternatively, the annular beadsor ridges can be of the same size or height but may accommodatedifferent needle diameters because of an overall step-wise tapering ofthe inner diameter or inner surface of the outlet tube 464 from big(proximal) to small (distal), thereby forming a tight fit around morethan one size needle diameter, anchoring or engaging a larger gaugeneedle more proximally in the outlet tube and smaller diameter needlesmore distally. Of course, the locations of bead 468 and groove 470 maybe reversed: bead 468 may be formed on cannula 466 b and groove 470along an inner surface 474 of tubular outlet port 464. Multiple annularbeads 468, 468′, 468″ may be formed along inner surface 474, spaced fromone another, to accommodate stylet needle assemblies 466, 466′, 466″with cannulas 468 b, 468 b′, 468″ of different diameters or gauges. Inthat case, inner surface 474 of outlet tube 464 may exhibitlongitudinally staggered sections, 474, 474′, and 474″ of respectivediameters increasing in diameter in a proximal direction, that is, froma free end 464 a of port 464 toward the respective port chamber.Typically needle stylet 466 a is made of stainless steel while cannula466 b and/or outlet tube 466 is made of an at least partially resilientpolymeric material, facilitating the snap-lock cooperation and formationof a seal.

Alternatively, multiple mutually spaced annular grooves 470 may beprovided along outer surface 470 of cannula 466 b. In another variation,needle assembly 466 and inner surface 474 of outlet port 464 may beformed with multiple co-acting pairs of beads and grooves all of thesame diametric or radial dimensions but axially spaced from one anotheralong the lengths of the needle assembly and the outlet port. Thesnap-lock coupling of bead 468 and groove 470 serves to not onlymaintain the high-flow cannula 466 b fixed to the respective vascularport 52, 252, 352, but to facilitate coupling operations and to closelyfit the cannula to the inner surface 474 of the respective outlet tube64, 264, 364 to prevent back flow. The horizontal- or lateralsidewall-access aperture as disclosed herein enables straight-line largebore needle-assembly cannula access to the outlet tube 464, 64, 264 364and the outlet tubes of all the vascular port devices disclosed herein,for enabling maximal flow rates relative to the perpendicular- ortop-access aperture which has greater frictional loss and turbulencerelated to flow through the capacious chamber with the needle access at90 degrees.

Any vascular access port described herein may be provided with areversible snap-lock mechanism such as bead 468 and groove 470. Otherkinds of reversible locking mechanisms well known to those skilled inthe art may be used in substitution for a bead and groove snap-lock. Forinstance, any outlet port or stem of a dual-access vascular portdisclosed herein may be provided with a screw-type locking mechanismwith mating male spiral threads and female spiral grooves in the outletstem and on the outer surface of a cannula of a non-coring needleassembly. Once the needle assembly cannula is engaged in the outlet portor stem, a user rotates the needle assembly, or at least the cannulathereof, clockwise or counter clockwise to engage and then in theopposite rotational direction to remove the needle assembly,particularly the cannula thereof. Alternatively, one may provide anyoutlet port or stem of a dual-access vascular port disclosed herein witha friction-fit locking mechanism with the outlet port or stem exhibitinga tapered inner surface of decreasing diameter, where a cannula of anon-coring needle assembly has a similarly tapered distal end. Thetapered distal end of the cannula and the correspondingly tapered innersurface of the outlet port or stem together form a cooperatingreversible locking mechanism. One of the cannula and the port,preferably the port or stem, is made of a metal while the other is madeof a resilient high-friction material such as rubber polymer. The needleassembly cannula is forced into the outlet port or stem and remainsstuck therein until a user pulls the needle assembly, particularly thecannula thereof to disengage the male-female friction lock and removethe needle assembly cannula. Other kinds of reversible lockingmechanisms with cooperating elements on the outlet port or stem of adual-mode vascular access port will occur to those skilled in the art.Typically, the cooperating elements include projections (male) andreceivers (female) such as one or more radially extending tongues thatinsert into L-shaped recesses requiring a distal translation and then arotation to lock and the reverse to unlock.

A number of options are available when utilizing the port devicedescribed herein for high flow access procedures such as apheresis ordialysis: two separate single lumen ports with one serving as the venousaccess and the second for the venous return; single lumen portplacement, with the port serving as a venous access and use ofperipheral intravenous cannulation for the venous return; or placementof a dual lumen port with both venous access and return capabilities.The snap-lock needle mechanism also facilitates and supports stableadvancement of a wire or other endoluminal device through the horizontalor lateral or straight-line access needle for the performance of thevarious methods and procedures described herein, which facilitate portplacement, maintenance of secondary patency including fibrin sheathstripping and microbrush/microballon utilization, port catheterrepositioning, port removal, and port exchange, all enabled by thehorizontal access aperture.

A snap-lock needle mechanism as contemplated herein may typicallyinclude male and female elements as depicted in FIG. 34 . The outlettube may be made of resilient polymeric material that enhances theoperability of the snap-lock mechanism. The outlet tube may be furthertapered distal to the snap-lock mechanism to accommodate a smallerintravascular catheter (which is fitted over the distal outlet tube tipwith a locking collar) as needed.

FIG. 35 depicts an implantable vascular port apparatus or device 502,which includes a frusto-conical main port body 506 having afrusto-conical internal chamber 504 formed therein. The main port body506 has a sidewall 508 with a conical outer surface 510. The port body506 and port chamber 504 may be of similar or differing shapes and orsizes respectively. FIG. 35 shows a frusto-conical port chamber 504 andfrusto-conical outer port body 506. The main port body 506 has twopenetrable septa 512 and 514 extending across and closing respectiveapertures 516 and 518. Aperture 516 is a perpendicular-access aperturesimilar to that of conventional ports, while aperture 518 constitutes astraight-line-access aperture primarily for high-flow applications andthe performance of various interventions to facilitate initial portplacement, port catheter repositioning, maintenance of secondary portpatency, port removal, and port exchange. The septa 512 and 514 areformed from a resiliently deformable material such as siliconeelastomer. The mounting of the septa 512 and 514 to the port body 506may be as described above. The port body 506 is formed from abiocompatible material, such as titanium alloy or other biocompatiblecorrosion-resistant metal, or from a biocompatible plastic. A titaniumliner may be used along a floor or bottom surface 520 of port chamber504 when plastic is utilized for the port body 506. Access aperture 518and an outlet tube 522, with an inner end defining an outlet aperture524, is located midway between a lower wall or floor 526 and an upperwall 528 of port body 504.

A vascular access port 502′ shown in FIG. 36 is the same as the port 502of FIG. 35 , and the reference numerals designating various componentparts are the same. However, in the port of FIG. 35 , access aperture518, outlet aperture 524 and outlet tube 522 are located closer to upperwall 528 than to lower wall or floor 526.

A vascular access port 530 depicted in FIG. 37 is similar to the accessports 502 and 502′ of FIGS. 35 and 36 . Except for the differentreference numerals as shown, port 530 exhibits the same structuralfeatures as ports 502 and 502′. Instead of a frusto-conical internalchamber 504, port 530 has an ovoid or ellipsoidal internal chamber 532.An outlet tube 534 joins chamber 532 substantially normal to theinternal surface of the chamber. In contrast, a modified vascular accessport device 536 illustrated in FIG. 38 has an outlet tube 538 that isconnected tangentially to the ovoid or ellipsoidal internal port chamber532, minimizing turbulent flow within the chamber. Port device 536exhibits another feature that may be incorporated into any of the portdevices disclosed herein, namely, a frusto-conical, conical orhemisphere shaped recess (inwardly tapering recess) 537, within the portbody comprising the lateral access aperture, provided at an inner endwith a self-sealing septum or membrane 539 for needle penetration at itsjunction with the inner chamber wall. Recess 537 has an edge 537′ at anouter end that facilitates tactile detection via palpation of apatient's dermal and underlying tissues (palpable depression). Recess537 typically has a frusto-conical surface (not separately designated),although other shapes may be used.

As illustrated in FIG. 39 , an implantable vascular port apparatus ordevice 540 includes a main port body 541 having a frusto-conical outersurface 543 and an ovoidal or ellipsoidal internal chamber 548. Internalchamber 548 is formed with an outlet aperture 546 through which theinternal chamber is in communications with a bent, double angled, orsnaking outlet tube 542, such that it ultimately exits the port flush ornearly flush with the port floor. Outlet tube 542 has an upstreamportion 544 contiguous or continuous with outlet aperture 546 and adownstream portion 550 preferably disposed at or near a lower wall 547of port body 541.

Port body 541 (FIG. 39 ) has two penetrable septa, an upper or topseptum 553 for perpendicular low-flow access and a lateral septum 554for transverse straight-line access utilizable in high-flowapplications. Septa 553 and 554 extend across and cover respectiveapertures 551 and 552. Septa 553 and 554 are formed from a resilientlydeformable material such as silicone elastomer. The mounting of thesepta 553 and 554 to the port body 541 may be as described above. Theport body 541 is formed from a biocompatible material, such as titaniumalloy or other biocompatible corrosion-resistant metal, or from abiocompatible plastic. A titanium liner may be used along a floor orbottom surface 548′ of internal chamber 548 when plastic is utilized forthe port body 541.

Port apparatus or device 540 (FIG. 39 ) facilitates straight-line needledeployment in that both the access aperture 552 and the outlet aperture546 are located near the upper end of the port device. Upstream portion544 of outlet tube 542 is co-linear with access aperture 552 and itsassociated septum 554. The disposition of the downstream portion 550 ofoutlet tube 542 at the bottom or lower wall 547 of the port deviceminimizes or eliminates tilting of the device by a catheter connected tooutlet tube 542.

FIG. 40 depicts an implantable vascular port apparatus or device 560,which includes a frusto-conical main port body 562 having afrusto-conical internal chamber 564 formed therein. The main port body562 has a sidewall 566 with a conical outer surface 568. The main portbody 562 has two penetrable septa 570 and 572 extending across andclosing respective apertures 574 and 576. Aperture 574 is aperpendicular-access aperture similar to that of conventional ports,while aperture 576 constitutes a straight-line-access aperture primarilyfor high-flow applications and the performance of various interventionsto facilitate initial port placement, port catheter repositioning,maintenance of secondary port patency, port removal, and port exchange.The septa 570 and 572 are formed from a resiliently deformable materialsuch as silicone elastomer. The mounting of the septa 570 and 572 to theport body 562 may be as described above. The port body 562 is formedfrom a biocompatible material, such as titanium alloy or otherbiocompatible corrosion-resistant metal, or from a biocompatibleplastic. A titanium liner may be used along a floor or bottom surface578 of port chamber 564 when plastic is utilized for the port body 562.Access aperture 576 is located at an upper end of sidewall 566, while anoutlet aperture 580 is disposed lower down along sidewall 566. An outlettube 582 communicating with internal chamber 564 via outlet aperture 580is inclined downwardly, co-linear with a straight-line insertion path583 for a needle extending from access aperture 576 to outlet aperture580. The design facilitates entrance into the straight-line accessaperture 576 relative to the skin surface while at the same timeminimizing tilting of the port by the weight of the exiting catheter.

FIG. 41 depicts an implantable modified frusto-conical vascular accessport 584 with a downwardly inclined needle insertion path 585 similar tothat of the frusto-conical port 560. Port 584 has a different externalgeometry with a skewed conical sidewall 586 having a straight-lineaccess aperture 588 and associated septum 590 directed at an angle forfacilitating access. The skewed conical sidewall 586 may furtherfacilitate entrance into the straight-line access aperture 588 relativeto the skin surface while at the same time minimizing tilting of theport by the weight of the exiting catheter. Otherwise, port 584 exhibitsthe same structural feature as port 560, including the geometry of theinternal chamber 564.

FIG. 42 depicts a modified frusto-conical vascular access port 584′similar to port 584 of FIG. 41 but with an ovoid or ellipsoidal internalchamber 592, while FIG. 43 shows a modified frusto-conical vascular port594, similar to port 584′ of FIG. 42 , with an upper sidewall portionhaving two mutually inclined facets 596 and 597 at an upper end and asteep angle access aperture 598, relative to the port floor, located inthat curved sidewall portion. Port 594 also has a slanted andtangentially oriented outlet tube 600 relative to the ovoid orellipsoidal inner chamber 592, optimizing flow dynamics within thechamber.

FIG. 44 illustrates a double lumen implantable vascular access port 602with two internal port chambers 604, 605 separated by a midline divideror partition 606 with two perpendicular-access apertures (not shown) andtwo straight-line-access apertures 616 and 618. The port 602 includes amain port body 610 that is elliptic frusto-conical or oblate sphericalin configuration and that has four penetrable septa, namely twoperpendicular-access septa (not shown) covering respective apertures(not shown), similar to conventional double ports and the other doublelumen port pursuant to the invention described herein (FIG. 12 ), aswell as two straight-line-access septa 612 and 614 over apertures 616and 618, primarily for high-flow applications and for the performance ofvarious interventions to facilitate port placement, port repositioning,maintenance of secondary port patency, port removal, and port exchange.The septa 612, 614 are formed from a resiliently deformable materialsuch as silicone elastomer and may include a thickened central portion(not illustrated), anchored or mounted as described above.

Needle insertion paths 620 and 622 from apertures 616, 618 and septa612, 614 to round outlet apertures 624 and 626 at the upstream sides ofsemi-cylindrical outlet tubes 628 and 630 are straight lines preferablyangled in towards one another, so as to provide space outside septa 612,614 for manipulating two needles simultaneously, if necessary. Alsostraight-line insertion paths 620 and 622 may be angled downwardly (asillustrated in FIGS. 40-43 ) to place the access apertures 616, 618closer to the skin surface to thereby facilitate aperture locating andneedle deployment. Such a double lumen vascular access port may be usedin carrying out an apheresis or dialysis procedure. Each round outletaperture may transition into respective semicircular outlet tube lumens.In another version each round outlet aperture may transition into twoseparate round parallel or near parallel outlet tubes and outlet tubelumens, perhaps necessitating less inward angling of the needleinsertion pathways. The separate outlet stems may be attached toseparate intravascular catheters in this alternative device version.

As depicted in more detail in FIG. 45 , port body 610 of the doublelumen implantable vascular access port 602 of FIG. 44 has passageways orchannels 632 and 634 that extend in a sidewall 636 of the port body fromrespective outlet apertures 624 and 626 to respective lumens 638 and 640of outlet tubes 628 and 630. Passageways 632 and 634 are provided withinwardly projecting annular beads 642 and 644 that cooperate withannular grooves on a round stylet needle cannula (see FIG. 34 andassociated description) to reversibly lock the needle cannulas to theport body 610 for high flow applications. The double lumen compositeoutlet tube 628, 630 contains a midline groove or slit 645 (not visiblein FIG. 44 ), which accepts a midline divider (253, see FIGS. 15 and 16) of a double lumen catheter (28, FIGS. 15 and 16 ).

As illustrated in FIG. 46 , an implantable vascular access port 646representative of any port described herein may be provided with varyingdegrees of radio-opacity or radio-translucency to facilitate accessunder fluoroscopic guidance. A major portion 648 of a port body 650 hasa first predetermined degree of radio-opacity. A lateral access aperture652 and its associated septum 654, as well as an outlet aperture 656 andoptionally a top access aperture 658 and its associated septum 660,exhibit a second predetermined degree of radio-opacity. The port bodymay be provided with edge regions 662, 664 and optionally 666 thatextend about and define lateral-access aperture 652, outlet aperture 656and top access aperture 658, respectively, the edge regions 662, 664,666 having a third predetermined degree of radio-opacity. At least oneof the second and the third predetermined degrees of radio-opacitydiffers substantially from the first predetermined degree ofradio-opacity. In other words, the radio-opacity (concomitantlyradio-translucence) of the different apertures 652, 656 and 658 vary soas to enable fluoroscopic visualization. Thus lateral access aperture652 and outlet aperture 656 may be readily localized visually during aneedle insertion procedure particularly for high-flow applications suchas apheresis and dialysis. Radio-opacity may vary between essentiallyzero (radio-translucence) and essentially 100% (completelyradio-opaque). The degrees of radio-opacity are understood asqualitative in that each degree of radio-opacity can lie within anumerical or percentage range but where the degrees differ for enhancingvisualization, the respective ranges of radio-opacity do not overlap.Thus the various physical features are fluoroscopically distinguishable.It is to be understood that the radio-opacity of lateral access aperture652 and top (vertical) access aperture 658 is the same as, anddetermined by, the radio-opacity of the associated septum 654 and 660.

As illustrated in FIG. 47 , a double lumen vascular access port 670 hastwo internal chambers 672, 674 separated by a divider or partition 676as discussed herein above with reference to FIG. 44 . A port body wall678 has two cylindrical channels 680, 682 defining respective outletapertures (not separately designated) and provided with respectiveannular resilient beads 684, 686 for insertion in snap-lock fits intogrooves on outer surfaces of stylet-needle assembly cannulas (notshown). Two separate outlet tubes 688 and 690 are attached to orintegral with port body wall 678 with lumens 692 and 694 coaxial andcommunicating with respective channels 680, 682. In a modification ofthe embodiment of FIG. 47 , the snap-lock beads 684, 686 may be providedin the outlet tube lumens 692 and 694 rather than in channels 680, 682.

As depicted in FIG. 48 , an outlet tube 700 for use with dual lumenvascular access port 252 in place of double lumen hollow outlet tube 264(FIGS. 12-16 ) includes two lumens 702, 704 each with a distal end 706,708 having a D-shaped cross-section and a proximal end portion 710, 712with a circular cross-section. Proximal end portions 710, 712 are formedinternal with inwardly projecting annular beads 714, 716 for removableinsertion in annular grooves in cannulas (not shown) of respectivestylet needle assemblies (not shown). Between each distal end 706, 708and the respective proximal end portion 710, 712, the respective lumen,702, 704 is formed with a transition section (not separately designated)including a half surface 718, 720 that gradually morphs from a linearconfiguration at distal end 706, 708 to a semi-circular profile atproximal end portion 710, 712. Thus outlet tube 700 accommodatescylindrical needle cannulas at an inner or proximal end and aconventional bifurcated catheter (see 284 in FIG. 15 ) at an outer ordistal end. Outlet tube 700 may taper from a wider proximal end at theport body to a smaller diameter at the distal end where theintravascular catheter is joined to the outlet tube.

What is claimed is:
 1. An implantable vascular access port, comprising:a port body having a lower or floor wall, an upper wall opposed theretoand at least one sidewall extending between said upper wall and saidlower or floor wall, said port body having at least one internalchamber, said port body having at least one outlet aperture formed insaid at least one sidewall in communication with said at least oneinternal chamber, said port body having at least one first access pointor location defining an at least partially horizontal-access path ordirection to said at least one outlet aperture through said at least oneinternal chamber, said port body being formed in said upper wall with atleast one second access point or location defining a perpendicular- orvertical-access path or direction substantially perpendicular to saidlower or floor wall; and at least one hollow outlet tube attached to theport body and in fluid communication with said at least one internalchamber and said at least one outlet aperture, wherein at least one ofsaid at least one hollow outlet tube and said port body proximate saidat least one outlet aperture is configured internally for cooperatingwith an outer surface of a distal end portion of a needle cannulainserted through said first access point or location to removably orreversibly lock the cannula, upon an insertion of said distal endportion thereof into said at least one internal chamber, to said atleast one hollow outlet tube or said port body proximate said at leastone outlet aperture so that the cannula communicates with said lumen ofsaid at least one hollow outlet tube.
 2. The implantable vascular accessport of claim 1 wherein said at least one of said at least one hollowoutlet tube and said port body proximate said at least one outletaperture is formed with a male or female locking element and said outersurface of said needle cannula is provided with a female or male lockingelement, respectively.
 3. The implantable vascular access port of claim1 wherein said at least one internal chamber is provided in said atleast one sidewall with at least one outwardly tapering chamberextension having a first transverse dimension at said at least oneinternal chamber and a second transverse dimension at said at least oneoutlet aperture, said first transverse dimension being larger than saidsecond transverse dimension, said at least one outlet aperture beingspaced from said at least one internal chamber by a length or heightdimension of said at least one outwardly tapering chamber extension. 4.The implantable vascular access port of claim 3, wherein said at leastone outwardly tapering chamber extension is aligned with said at leastone first access point or location such that during a medical procedurewhen a tip portion of a hollow needle cannula is inserted into said atleast one internal chamber, a surface of said at least one outwardlytapering chamber extension passively guides the hollow needle cannula orwire toward said at least one outlet aperture, into said at least onehollow outlet tube, enabling wire advancement into a catheter attachedto said at least one hollow outlet tube.
 5. The implantable vascularaccess port of claim 1, wherein said at least one first access point orlocation comprises a palpable inwardly tapering recess.
 6. Theimplantable vascular access port of claim 1, wherein said at least onesidewall has, on a side opposite said at least one outlet aperture, anouter surface having a lower portion and an upper portion bearingdifferent angles relative to said upper wall and said lower or floorwall, said upper portion being slanted from said lower portion towardssaid upper wall.
 7. The implantable vascular access port of claim 6,wherein said at least one hollow outlet tube has, at an inlet endproximal said at least one internal chamber, an axis co-linear with saidat least partially horizontal-access path or direction.
 8. Theimplantable vascular access port of claim 1, wherein said at least onesidewall has an outer surface with at least a portion with a profiletaken from the group consisting of straight, sloped, and curved.
 9. Theimplantable vascular access port of claim 1, wherein: a major portion ofsaid port body has a first predetermined degree of radio-opacity; saidat least one first access point or location and said at least one outletaperture exhibit a second predetermined degree of radio-opacity; saidport body has edge regions extending about and defining said at leastone first access point or location and said at least one outletaperture, said edge regions having a third predetermined degree ofradio-opacity; and at least one of said second predetermined degree ofradio-opacity and said third predetermined degree of radio-opacitydiffers substantially from said first predetermined degree ofradio-opacity.
 10. The implantable vascular outlet port of claim 1,further comprising a catheter attached to said at least one hollowoutlet tube, and at least one medical instrument or tool taken from thegroup consisting of guide wires, needles, microbrush or microballoondevices, said at least one medical instrument or tool extending throughsaid at least one first access point or location, said at least oneinternal chamber, said at least one outlet aperture, and said at leastone hollow outlet tube, and said catheter for the performance of anintravascular procedure.
 11. The implantable vascular access port ofclaim 1 wherein said at least one of said at least one hollow outlettube and said port body proximate said at least one outlet aperture atleast in part comprises an elastomeric material.
 12. The implantablevascular access port of claim 1 wherein: said at least one first accesspoint or location has a position at an upper end of said port body; saidat least one outlet aperture is disposed lower down than said at leastone access aperture along said sidewall; and said at least partiallyhorizontal-access path or direction to said at least one outlet aperturethrough said at least one internal chamber is inclined downwardly at anangle.
 13. An implantable vascular access port, comprising: a port bodyhaving a lower or floor wall, an upper wall and at least one sidewallextending between said upper wall and said lower or floor wall, saidport body having at least one internal chamber, said port body having atleast one outlet aperture formed in said at least one sidewall thereofin communication with said at least one internal chamber, said port bodyhaving, substantially opposite said at least one outlet aperture, atleast one access point or location defining an at least partiallyhorizontal-access path or direction to said at least one outlet aperturethrough said at least one internal chamber; at least one septum attachedto said port body and covering or closing said at least one internalchamber at said at least one access point or location; and at least onehollow outlet tube attached to the main port body and in fluidcommunication with said at least one internal chamber and said at leastone outlet aperture, wherein at least one of said at least one hollowoutlet tube and said port body proximate said at least one outletaperture is configured internally for cooperating with an outer surfaceof a distal end portion of a needle cannula inserted through said atleast one access point or location, to removably or reversibly lock thecannula, upon an insertion of the distal end portion thereof into saidat least one internal chamber, to said at least one hollow outlet tubeor said port body proximate said at least one outlet aperture so thatthe cannula communicates with said lumen of said at least one hollowoutlet tube.
 14. The implantable vascular access port of claim 13wherein (i) said at least one of said at least one hollow outlet tubeand said port body proximate said at least one outlet aperture and (ii)said outer surface of said needle cannula are adapted to cooperate withone another in a lock mechanism that facilitates needle cannulastability, (i) said at least one of said at least one hollow outlet tubeand said port body proximate said at least one outlet aperture and (ii)said outer surface of said needle cannula being configured to create atight seal with one another to enable backflow and turbulence preventionin high-flow procedures.
 15. The implantable vascular access port ofclaim 13 wherein at least one of (i) said at least one of said at leastone hollow outlet tube and said port body proximate said at least oneoutlet aperture and (ii) said outer surface of said needle cannula atleast in part comprises an elastomeric material.
 16. The implantablevascular access port of claim 13 wherein (i) said at least one of saidat least one hollow outlet tube and said port body proximate said atleast one outlet aperture and (ii) said outer surface of said needlecannula are configured to cooperate with one another to reversibly fixsaid needle cannula to said port body, thereby facilitating wirenavigation through said needle cannula, said at least one internalchamber and said at least one hollow outlet tube and into a catheterattached thereto and also facilitating longitudinal migration ormovement of said port body and said catheter over a wire for portimplantation, repositioning, removal, or exchange.
 17. The implantablevascular access port of claim 13 wherein said at least one of said atleast one hollow outlet tube and said port body proximate said at leastone outlet aperture is provided internally with at least one firstlocking element configured for cooperating with at least one secondlocking element on said outer surface of said needle cannula, toremovably or reversibly lock the cannula to said at least one hollowoutlet tube or said port body so that the cannula communicates with alumen of said at least one hollow outlet tube.
 18. The implantablevascular access port of claim 13 wherein: said at least one access pointor location has a position at an upper end of said port body; said atleast one outlet aperture is disposed lower down than said at least oneaccess aperture along said sidewall; and said at least partiallyhorizontal-access path or direction to said at least one outlet aperturethrough said at least one internal chamber is inclined downwardly at anangle.
 19. An implantable vascular access port, comprising: a port bodyhaving a lower or floor wall, an upper wall and at least one sidewallextending between said upper wall and said lower or floor wall, saidport body having at least one internal chamber, said port body having atleast one outlet aperture formed in said at least one sidewall thereofin communication with said at least one internal chamber, said port bodyhaving, substantially opposite said at least one outlet aperture, atleast one access point or location defining an at least partiallyhorizontal-access path or direction to said at least one outlet aperturethrough said at least one internal chamber; at least one septum attachedto said port body and covering or closing said at least one internalchamber at said at least one access point or location; and at least onehollow outlet tube attached to the main port body and in fluidcommunication with said at least one internal chamber and said at leastone outlet aperture, wherein: said at least one access point or locationhas a position at an upper end of said port body; said at least oneoutlet aperture is disposed lower down than said at least one accessaperture along said sidewall; and said at least partiallyhorizontal-access path or direction to said at least one outlet aperturethrough said at least one internal chamber being inclined downwardly atan angle.
 20. The implantable vascular access port of claim 19 whereinat least one of said port body and said at least one hollow outlet tubeis configured internally for cooperating with an outer surface of adistal end portion of a needle cannula inserted through said at leastone access point or location to removably or reversibly lock thecannula, upon an insertion of said distal end portion thereof into saidat least one internal chamber, to said at least one hollow outlet tubeor said port body so that the cannula communicates with said lumen ofsaid at least one hollow outlet tube.